A small cloud moves slowly through the air in a hospital operating room （手术室）.In the room a patient with cancer（癌症），lies on a table.The cloud is all around the patient，covering her body and filling her lungs（肺）.The cloud is not smoke.It is made of millions of nano﹣robots（纳米机器人）.These tiny robots move from cell （细胞） to cell in the patient's body，killing the cancer.
Fighting cancer with nano﹣robots is only an idea today，but scientists say that it could be possible in the future.Using nano﹣robots for good purposes such as fighting the illness or repairing the environment may be the way to many of today's problems.
However，nano﹣robots could be a dangerous risk as well.Because nano﹣robots are so tiny，they will have to work in large teams of many thousands to many millions.For this reason，nano﹣robots will have to be programmed（被编程）to build themselves.Scientists will not have the ability to build millions of nano﹣robots one by one.
This ability to re﹣produce is making some scientists worried.What will happen if something goes wrong in the programming？Quite a lot of crazy nano﹣robots would be far worse than any illness.Some people think that if they get out of control，nano﹣robots could make the Earth gone.
What should be done？Should we continue researching nano﹣robots or should we search for other methods？This is one of the many difficult decisions that we have to make in the future.
（1）What is the cloud in the passage？
A.Smoke in the air.
B.Millions of nano﹣robots.
C.Something full of drops of water.
D.Clothes to cover a patient.
（2）What does the underlined word it in Paragraph 2 refer to（指代）？
A.Fighting cancer with nano﹣robots.
B.Moving from cell to cell.
C.Killing the cancer.
D.Repairing the environment.
（3）Which of the following is NOT the reason why some scientists are worried about using nano﹣robots？
A.Nano﹣robots have the ability to build themselves.
B.Something may go wrong in the programming.
C.Scientists have to build millions of nano﹣robots one by one.
D.Nano﹣robots in large teams may be out of control.
（4）What does the writer think of using nano﹣robots in the future？
A.He agrees to the idea.
B.He disagrees to the idea.
C.He doesn't talk about his own opinion.
D.He is crazy about it.
（5）What is the best title？
A.Future Robots
B.The Ways to Fight Cancer
C.Nano﹣robots in Use
D.A Cloud of Hope and Danger
A Pioneer for all People
Though he was one of China's most famous scientists，Yuan Longping considered himself a farmer，because he worked the land to do his research.
Known as "Father of Hybrid Rice （杂交水稻）"，Dr Yuan graduated from Southwest Agricultural （农业的） College in 1953.From then on，finding ways to grow more rice was his life goal.As a young man，he saw the great need for increasing the rice production.At that time，hunger was a serious problem in many parts of the countryside.Dr Yuan searched for a way to get more rice with the same size of the fields.In 1974，he became an agricultural pioneer in the world to grow rice that has high production and that is called super hybrid rice.In the 1980s，he went around the world and gave advice about growing rice to farmers in other countries.In 2004，he won the World Food Prize for his work.
Dr Yuan was quite satisfied with his life.He would much rather keep time for his hobbies.He enjoyed playing the violin，swimming and reading.Spending money on himself meant very little to him，so he gave millions of yuan to help some researchers with their research in farming.
Long ago Dr Yuan had a dream about rice plants as tall as sorghum （高粱） .With his hard work，he grew the rice that could feed more people.President Xi Jinping praised him for his great contributions （贡献） to China's food safety and world corn development.
Answer the questions according to the passage. （必须使用完整语句作答）
（1）Why did Dr Yuan consider himself a farmer？
（2）What is Dr Yuan known as？
（3）When did Dr Yuan win the World Food Prize？
（4）How did Dr Yuan help other researchers？
（5）What did Dr Yuan make contributions to according to President Xi Jinping？
China has named the nation's first Mars rover（火星车）Zhu Rong.For all of us，Zhu Rong is a well﹣suited name.
In an ancient Chinese story，Zhu Rong had the face of a man and the body of an animal.He rode on two dragons.When he had a big fight with Gong Gong，the god of water，Zhu Rong won.But after the fight，the human world came into complete darkness.Then he brought fire from heaven（天国）to the world.
"Zhu Rong is regarded as the earliest god of fire in traditional Chinese culture，" a space official said. "The first Mars rover was named Zhu Rong.The name symbolizes（象征）light and hope for space exploration（探索）in our country，and means to guide humans to continue exploration."
After leaving the earth last summer，Zhu Rong circled Mars for several months and landed on it in May.In recent years，our country has sent up the world's first quantum satellite（量子卫星），and Chang'e﹣4 has made a soft landing on the moon.We have made great progress in space technology and will soon start building our own space station.
（1）What Zhu Rong brought from heaven to the world was .
| A． |
fire |
| B． |
wars |
| C． |
water |
| D． |
animals |
（2）For China's space exploration，the name Zhu Rong symbolizes .
| A． |
a big fight |
| B． |
complete darkness |
| C． |
light and hope |
| D． |
Chinese culture |
（3）The underlined word "it" in the last paragraph refers to" "
| A． |
the earth |
| B． |
Mars |
| C． |
the moon |
| D． |
the sun |
（4）According to the passage，we can infer that .
| A． |
Zhu Rong is a bad person in an ancient Chinese story |
| B． |
China has made great progress in space technology |
| C． |
the writer is proud of China's space technology |
| D． |
the official doesn't like the name Zhu Rong |
Over the last six months， the coronavirus pandemic（冠状病毒疫情） has affected different countries and regions in different ways．Here， we'll take a look at a few of the most important events that have happened．
Italy shuts down
On March 10， the Italian government decided to put the whole country on lockdownafter the number of cases（病例） in the country started increasing quickly， people were suggested not leaving their home．The first case was detected（检测到） as early as January 31．In the following weeks， the number of cases reached over 10， 000 by the time of the lockdown．The lockdown affected 16 million people across the country．Italy was one of the first of many countries that cami ed out lockdown s to prevent the spread of the virus．
WHO declares pandemic
On March 11， World Health Organization（WHO） offically characterized（描述） COVID﹣19 as a pandemic．This was because of a growing number of cases around the world．By this time， there were more than 20， 000 cases in Europe， including 1， 000 deaths， as well as 1， 000 cases in the US．
Summer Olympics delayed
On March 24， President of the International Olympic Committee（IOC） Thomas Bach announced the 2020 Summer Olympic Games， which were planned to be held in Tokyo， would be delayed until the following year in the interest of protecting public safety．
US hits over l million cases
On April 28， the US recorded officially over one million COVID﹣19 cases nationwide．This came just four days after it was announced that the virus had resulted in over 50， 000 deaths across the country．The virus spread rapidly across the country， as the first case had been recorded three months earlier．
根据短文内容，选择最佳答案．
（1）The events in the passage are all connected with ．
| A． |
Italy's lockdown |
| B． |
US cases |
| C． |
Olympic games |
| D． |
the coronavirus pandemic |
（2）In paragraph 2， the underlined word "lockdown" probably means ．
| A． |
封城 |
| B． |
控制 |
| C． |
关押 |
| D． |
锁定 |
（3）COVID﹣19 was officially announced as a pandemic because it ．
| A． |
caused the lockdowns |
| B． |
had a growing number of cases in the world |
| C． |
could result in death |
| D． |
spread quickly in Europe |
（4）2020 Summer Olympic Games in Tokyo will be delayed because ．
| A． |
people may not go during the pandemic |
| B． |
the cases in Asia increased quickly |
| C． |
it hasn't been well﹣prepared |
| D． |
it's necessary to protect public safety |
（5）It took for the number of COVID﹣19 cases in the US to reach over one milion．
| A． |
four days |
| B． |
twenty﹣eight days |
| C． |
three months |
| D． |
four months |
Since May 8， Boston Dynamics， doglike robot， Spot， has been in use at BishanAng Mo Kio Park in Singapore to help encourage social distancing during the COVID19 pandemic （新冠肺炎疫情） according to a report in the South China Morning Post．
Singpore’s government is funding the experiment of the robotic dog， which will last for two weeks at the park during offpeak（非高峰的） hours．
"The robot isn’t enforcing （强制 ）． It’s just giving people information and encouraging them， "Boston Dynamics founder Marc Raibert told CNBC． "When Spot is patrolling（巡逻）the area， there’s a parks officer nearby who can do whatever enforcement he decides is suitable． "
Cameras fixed on Spot will scan the surroundings and help officers work out the number of visitors in the park， but they cannot read faces and won’t collect any personal information． It also carries a loudspeaker to broadcast a prerecorded message to remind visitors of the importance of social distancing．
Without enough manpower， Singapore is turning to robotics to reduce the manpower required for park patrols and remind people about the risks they may be putting themselves and others in．
The question， however， is whether their use of Spot will be a good tool or will or only attract more people to it instead．
If the twoweek experiment proves successful， the government will consider using Spot at the park during peak hours． Singapore will also do studies to see if it’s worth using other Spots in other parks． Already， Singapore engineers are trying to improve Spot， making it tell if people are together in a group or strangers passing on the grass．
No one knows if Spot will stay after the pandemic is gone， but one thing is for sure： the robot is the hardest working dog in the world．
（1）Why is Spot used at BishanAng Mo Kio Park？
A． To draw visitors， attention to it．
B． To help encourage social distancing．
C． To read and record visitors， faces．
D． To help collect private information．
（2）The underlined word "they" in Paragraph 4 refers to（指的是） ．
A． visitors
B． strangers
C． cameras
D． officers
（3）What can we learn from the last 3 paragraphs？
A． The experiment is still in progress．
B． The use of Spot proves to be a good tool．
C． Spot will stay after the pandemic is over．
D． Singapore will no longer need other Spot robots．
（4）According to the passage， which of the following is TRUE？
A． Spot scares people into keeping a distance in public．
B． Spot patrols the park for two weeks during peak hours．
C． Spot can tell people together in a group from strangers passing by．
D． The parks officer nearby decides on the enforcement instead of Spot．
Xiao Liuying is an old man living in a village near the Yangtze River． He used to be a fisherman． But now he is head of a voluntary（志愿的） team that cleans waste from the Yangtze river．
To protect finless porpoises（江豚） and the Yangtze River， the government has stopped people from fishing on the river．In 2019，Xiao Liuying formed the voluntary team with 12 other fishermen．Today the team has more than 50 members．All of them are over 60 years old． "We want to protect the river while we can，" said Xiao．
Every week， the team go along the river to collect waste and make sure no one is fishing on the river．Some of the waste they collect is sent to the disposalstation，while some that can be reused is sold．So far， they have cleaned over 50 tons of waste， Thanks to their hard work， the Yangtze River is getting clearer．
（1）How many members were there in the team when it was formed？
A．12．
B．13．
C．50．
D．62．
（2）What does the underlined word "disposal" in Paragraph 3 mean？
A．处理．
B．传播．
C．救护．
D．保养．
（3）What is the best title（标题） for the text？
A． Fishing on the Yangtze River．
B． Tons of Waste in the Yangtze River．
C． Reasons for Protecting the Yangtze River．
D． A Voluntary Team Protecting the Yangtze River．
It seems that food deliverymen （送货员） are always rushing in haste.We can always see them running every minute，and they seem to have lots of things to do the next minute.They wear blue，red or yellow helmets （头盔） and many of them don't follow traffic rules.They drive on the wrong side of the road and run red lights.They use mobile phones when they are driving.
However，not everything goes well with food deliverymen.In the first half of 2017，food deliverymen had 76 traffic accidents in Shanghai.That means every two and a half days，a food deliveryman will die or get hurt on the road.
What makes deliverymen take such risks？The strict rules of the food delivery companies and the worried customers may be the answer.Many companies will fine （罚款） a deliveryman up to 2，000 yuan if he can't deliver the food on time，reported China Daily.Fines also go to those who get bad reviews from customers.
To solve the problem，food delivery service companies need to do some changes.Some cities are also taking action.Shanghai has asked companies to train their deliverymen on traffic rules and safety.Now in Shenzhen，if a deliveryman breaks traffic rules more than twice，then he can't do the job for a whole year.
（1）The underlined phrase "in haste" in Paragraph 1 probably means in Chinese.
| A． |
匆忙地 |
| B． |
慢慢地 |
| C． |
意外地 |
| D． |
犹豫地 |
（2）The first paragraph mainly tells us that many food deliverymen .
| A． |
work very hard |
| B． |
break traffic rules |
| C． |
are good at driving |
| D． |
use mobile phones too much |
（3）How many reasons are mentioned for deliverymen's taking risks of breaking traffic rules？
| A． |
Two. |
| B． |
Three. |
| C． |
Four. |
| D． |
Five. |
（4）If a food deliveryman ，the companies will fine him.
| A． |
drives too slowly |
| B． |
delivers food on time |
| C． |
obeys traffic rules |
| D． |
gets bad reviews from his customers |
（5）What is the main idea of the last paragraph？
| A． |
Traffic rules are too strict to deliverymen. |
| B． |
Food deliverymen cannot drive on important roads in the future. |
| C． |
Some cities are working to solve the problem and make things better. |
| D． |
All the companies in China train their deliverymen on traffic rules and safety. |
Daily News
Wild beavers （河狸） are back! Experts say that the wild beaver families are doing well． The beavers are even boosting wildlife and the environment!
Over ten years ago， a family of beavers turned up in a part of the river Otter， in Devon．No one knew exactly where they came from． It was a big surprise一wild beavers hadn't lived in England for around 400 years!
In 2015， the government allowed the beavers to stay there as part of a trial （试验）． They wanted to see if these animals could be reintroduced to the wild．The trial ends in February．Some scientists from the University of Exeter already say the beavers help the wildlife in the area． One scientist called it" an amazing story"．
A lot of this is because of dams． Beavers build dams along the river． This creates deep pools in the riverbed and slows the water down． Scientists say this is perfect for many different types of plants and animals! Many plants are growing near the beavers．Different types of animals are also becoming more and more in the river． Beavers also help make flooding less，scientists say．The beavers' dams slow down the speed of the river， especially after heavy rain．
There are， however， some problems． Beavers gnaw （咬，啃） on trees and this can harm them．Their dams can also sometimes create floods （洪水） on people's land．
Beavers aren't the only animals that are being reintroduced to the wild! In 2019， red squirrels were brought back to an area of the Scottish Highlands． Further away， the world's rarest （罕见的）duck， the Madagascar pochard， is making a comeback． It was set free into the wild on the African island in 2019 and is doing well．
Who knows what other animals might be making a comeback？
（1）Which of the following best explains "boosting" in paragraph 1？
A． building
B． spreading
C． helping
D． creating
（2）Why did the government want a trial first？ Because they wanted to ．
A． grow more plants along the river
B． build dams for the beavers in the wild
C． introduce the beavers to the wild
D． see if the beavers could be reintroduced to the wild
（3）What are the good things about wild beavers living on the river Otter？
A． They help plants grow and make flooding less．
B． They bring heavy rain and floods．
C． They gnaw on trees and harm them．
D． Their dams create floods on people's land．
（4）How many kinds of animals are mentioned in the news story which have been reintroduced to the wild？
A． One．
B． Two．
C． Three．
D． Four．
（5）How do you think animal lovers feel about the news？
A． Embarrassed．
B． Pleased．
C． Tired．
D． Disappointed．
The first emperor of China，Qin Shihuang，completed a huge number of projects during his rule.Between 221 and 210 B.C.，he started the building of the Great Wall.The emperor also ordered the building of a huge army of life﹣sized terracotta soldiers（士兵）.These，he hoped，would protect his tomb after his death.
Lost in Time
The soldiers in Xi'an's terracotta museum are today light brown，but they weren't always.They began as an army of red，blue，yellow，green，white，and purple.Sadly，most of the colors did not last to the present day.After being exposed（暴露）to air during digging，the coating under the paint began to fall off.The paint disappeared in less time than it takes to boil an egg，taking away with it important pieces of history.
New Technology
Now new technology is starting to show the army's true colors.Archeologists（考古学家）have recently discovered an area with more than a hundred soldiers.Many of these still have their painted features，including black hair，pink faces，and black or brown eyes.Chinese and German researchers have developed a chemical liquid（液体）to help save the soldiers' colors.After finding a soldier or another art piece，archeologists put the liquid on it. They then cover it in plastic.
Back to Life
Archeologists are also finding colors in the dirt around the soldiers.It's important not to do anything with the dirt，so the colors won't be lost. "We are treating the dirt as an art piece， "says Rong Bo，the museum's leading archeologist.The next challenge，says Rong Bo，is to find a way to use the colors onto the army﹣again.Once that happens，artists can bring Emperor Qin's army back to its full，bright colors.
（1）What is the passage mainly about？
A.The death of Emperor Qin Shihuang.
B.How the terracotta army was colored.
C.The true colors of the terracotta soldiers.
D.How the soldiers lived during Qin Dynasty.
（2）What does the underlined word "They" in the passage refer to？
A.Archeologists.
B.Artists.
C.Researchers.
D.Soldier.
（3）Which statement would Rong Bo probably agree？
A.The soldiers should stay in their present，brown color.
B.People should try to bring back the army's bright colors.
C.Archeologists can only guess at the soldiers' true colors.
D.Artists should be able to paint the soldiers in colors they want.
20，000 local sea creatures，from dolphins to otters（水獭）， await you at Aquarium（水族馆）of the Bay， San Francisco， CA（California）． When you see a river otter in the wild， you know that water system is healthy． Plus， they’re fun to watch! Here come the Aquarium’s popular and lovable river otters：Tahoe， Ryer and Shasta．
|
Me： I was born at the Oakland Zoo． I'm the halfbrother of Ryer． February 20， 2016 is my birthday and I joined the Aquarium，s river otter family in January， 2017． I'm named after Lake Tahoe， CA． How to find me： My fur is reddish in color． I am the youngest but the longest of the group． Hobbies： I enjoy playing with rope and toys， running and jumping around． |
|
Me： I'm a male river otter named after Ryer Island，CA．I was born in February，2013 at the Oakland Zoo and joined the Aquarium's otter team in 2014． How to find me： I have the widest head and the fattest face． Hobbies： What could be more fun than playing with my food and balancing rocks， and curling up with a warm blanket for a nap （a short sleep）？We river otters can sleep up to 18 hours a day． |
|
Me： I'm a 7yearold male river otter named after Mount Shasta， CA． I was saved from the fur trade in Louisiana and found a new home at the Aquarium in 2013． How to find me：I'm the largest of the otters．I have large closeset eyes．Which of the three is me？ Hobbies： I enjoy long afternoon naps， throwing leaves and sticks into the water． |
（1）The passage mainly talks about ．
A． how to play with the otters in the zoo
B． how to protect river otters in the wild
C． the importance of protecting river otters
D． the river otter family at Aquarium of the Bay
（2）Which of the following is TRUE about Ryer？
A． He was born in February， 2014．
B． He has large closeset eyes．
C． He is the halfbrother of Tahoe．
D． His fur is reddish in color．
（3）What do the three otters have in common？
A． They are all named after a place in California．
B． They were all born at the Oakland Zoo．
C． They can sleep at most 8 hours a day．
D． They enjoy playing with food and rocks．
With her eyes feeling increasingly tired and her vision blurry（视力模糊的），l6﹣year﹣old Tian Ting went to the hospital with her parents in January.She was shocked when she found out that her eyesight dropped from 5.0 to 4.6 in only a term. "A few of my friends have had the same experience lately，" Tian said.
In fact，poor eyesight among Chinese primary and high school students rose from 59.2 percent to 70.6 percent in the first six months of 2020，according to the Ministry of Education.
To protect students' eyesight，the Chinese government has worked out new requirements （要求） for school supplies （供应品） and equipments that will take effect （生效） on March 1，2022.For example，according to the requirements，the size of text in students' textbooks should be no smaller than nine﹣point.Teachers should also try not to use projectors （投影仪） or other multimedia equipments （多媒体设备） that are too bright，Beijing Daily reported.There are also requirements for desks and classroom lights.For example，these lights should give off （散发） as little blue light as possible.
Blue light is bad for our eyes，as it can kill the photoreceptor cells （光感器细胞） we need for vision，according to Harvard Medical School.Many of the electronic devices we use every day，like our phones and computer screens，give off blue light.
Chinese government has also taken other steps to protect students' eyesight in China.In May 2020，the National Health Commission urged schools to make sure that students have at least two hours of outdoor activity a day.
（1）In the first half of 2020，there were of students becoming short﹣sighted.
A.0.4%
B.11.4%
C.59.2%
D.70.6%
（2）The writer probably agrees that .
A.Schools use textbooks with the smaller size of text
B.Teachers use over﹣bright multimedia equipments
C.Students are made sure to have fewer than two hours of outdoor activity a day
D.Schools use lights that give off less blue light
（3）What's the best title of the passage？
A.How to protect us from illness.
B.How to have outdoor activity.
C.How to use electronic devices.
D.How to protect students' eyesight.
Here is the 6﹣day weather report in Suqian， Jiangsu Province．
Day |
Description |
Temperature |
Humidity（湿度） |
Monday June 29 |
|
27°C / 19°C |
91% |
Tuesday June 30 |
|
28°C / 21°C |
85% |
Wednesday July 1 |
|
27°C / 23°C |
79% |
Thursday July 2 |
|
25°C / 20°C |
89% |
Friday July 3 |
|
30°C / 24°C |
87% |
Saturday July 4 |
|
31°C/ 22°C |
92% |
（1）What's the weather like on Wednesday， July 1？
A． Mostly Sunny．
B． Partly Cloudy．
C． A． M． Showers．
D． P． M． Showers．
（2）The highest temperature appears on ．
A． Tuesday
B． Monday
C． Saturday
D． Thursday
（3）The humidity on Friday， July 3 is ．
A．92%
B．85%
C．79%
D．87%
Antarctica （南极洲） is at the southern end of the Earth． It is the coldest， driest and windiest place on our planet． What would it be like to live and work there？
On Oct 15， 50 Chinese researchers took a ship named Xuelong 2 from Shenzhen to Antarctica． Xuelong 2 is the first icebreaker （破冰船） made in China． It took two years to build Xuelong 2． It is reported that Xuelong 2 is one of the world's best research icebreakers．
Chinese researchers have been to Antarctica 35 times． Because of its unusual environment， researchers from around the world have been going there to do study （研究） for many years． Some studies can only be done in Antarctica． For example， there is little air pollution there． This makes it easier for scientists to study the weather， atmosphere （大气） and stars．
The study of Antarctica's geology （地质） is also important． Rocks in Antarctica can tell us what the weather was like long time ago， and help us understand how the Earth has changed over time． There are also many wild animals， such as penguins （企鹅），seals （海豹） and birds． Scientists can learn how animals live in cold places by studying them．
Xie Zhouqing is a professor at the University of Science and Technology of China． He was part of China's 15th research trip to Antarctica． He said， "Life in Antarctica is not easy．It is tiring and sometimes dangerous， but it is still quite fun．" He also said，"I studied how penguins walk， what they eat， and why they move from one place to another． I was excited to see the cute animals playing around． I hope my studies can help protect them．"
（1）What can we know from the first three paragraphs？
A． Antarctica is at the northern end of the Earth．
B． There is plenty of air pollution in Antarctica．
C． Xuelong 2 is the first icebreaker made in China．
D． Chinese scientists have been to Antarctica 45 times．
（2）What does the underlined word "it" mean in the fifth paragraph？
A． Life in Antarctica．
B． Rocks in Antarctica．
C． Fun in Antarctica．
D． Danger in Antarctica．
（3）What can we infer （推断） from the passage？
A． The weather in Antarctica hasn't changed over time．
B． Xie Zhouqing mainly studied geology in Antarctica．
C． Chinese researchers have done many studies in Antarctica．
D． The study in Antarctica can't help protect penguins and seals．
（4）Where does the passage probably come from？
A． A storybook．
B． A cooking guide．
C． A film review．
D． A science magazine．
Most viruses can be found and killed by our immune system as soon as they enter our bodies.However，some viruses，for example，the coronavirus，are sneaky.They are difficult to recognize and find.These viruses can cause deadly diseases，like COVID﹣19.Human﹣to﹣human transmission can easily occur，and pandemic will therefore break out.Vaccination is by now a simple，safe and effective way to protect us from the diseases.
▲Vaccines are something that "looks" exactly the same as the viruses，mainly made from the viruses that are weakened or killed.They will not make us really ill.They only stimulate and activate our immune system to work，telling it something harmful is coming in.The immune system will know what the "viruses" look like，and send B cells（lymphocytes）or antibodies to find and kill them.Meanwhile，B cells will remember them for the next kill.A vaccine may also give us passive immunity by providing B cells taken from an animal or a human to play the same role.
Scientists have developed more than 180 vaccines to fight against COVID49.The technical approaches of these vaccines can be a little different，but their aims are the same.
Take the inactivated vaccine as an example.In an inactivated vaccine，the coronaviruses are already killed or made into the ones unable to produce more new viruses.When the immune system "sees" them，it will try to kill them.The question is：without enough these viruses• how can B cells remember them？That's why we need to take the vaccine more than one time.Though this vaccine is safe，it might not be as effective as it is expected to be.
The live﹣attenuated vaccine is different.In this vaccine，the viruses are weakened，but they are alive.They can produce enough new viruses to train the immune system to kill and remember them，so people only need to take the vaccine once.The live﹣attenuated vaccine is considered the most effective，but there is a worry：what might happen once these viruses wake up？
Therefore，although vaccination is by now one of the best ways to protect us from COVID﹣19，it can be better.
（1）The coronavirus can .
| A． |
not be killed |
| B． |
not be found |
| C． |
cause deaths |
| D． |
stop pandemic |
（2）Which of the following can be the best topic sentence of Paragraph 2？
| A． |
Vaccination can provide us with B cells. |
| B． |
Vaccines are made from different viruses. |
| C． |
Vaccination can prepare us against viruses. |
| D． |
Vaccines won't make us ill as the viruses do. |
（3）Compared to the inactivated vaccine，the live﹣attenuated vaccine .
| A． |
needs taking more than once |
| B． |
is equally safe |
| C． |
contains viruses that are killed |
| D． |
is more effective |
（4）What can we learn from the passage？
| A． |
Vaccination is good enough to treat COVID﹣19. |
| B． |
The immune system can be more effective with vaccines. |
| C． |
The viruses in inactivated vaccines can make new viruses. |
| D． |
180 vaccines have been developed to fight against diseases. |
Rice is one of the most commonly eaten basic foods around the world.Buying it and cooking it is a daily matter.Yet for many，its presence has been a matter of life and death.It is a main food because it is easy to grow，besides low cost and convenience.A poor community in the developing world may find it difficult to bring in foreign fruits or raise cattle for meat，but it can almost certainly use the land it has in order to grow plenty of rice.
This was the great achievement of Yuan Longping，who passed away on May 22 this year.A great Chinese scientist，Yuan successfully developed what is known as "hybrid rice" which can produce up a 30% higher output.Yuan Longping was born in the year 1930，a time when China was very different.It was a nation，without modern industry，depending on the rice which they grew.The first few decades （十年） of his life were met with major social events，and a rapidly growing population that made food supply not last all the time.This experience left its mark on Yuan Longping，which made him focus on （关注） farming science and work on his research of hybrid rice.
His achievement would see the rice supply in China increasing from 56.9 million tons in 1950 to 194.7 million tons by 2017.By 1991，20% of the world's rice output came from hybrid rice，even if only being planted in 10% of fields.
Always remember，human development begins first with the most basic and sample things，such as developing rice.We should be thankful for scientific thinkers like Yuan.
（1）Why is rice a main food around the world？
（2）What did Yuan develop successfully？
（3）When was Yuan Longping born？
（4）What made Yuan focus on farming science？
（5）How many tons was the rice supply in China by 2017？
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