One in 400 children in the United States has diabetes(糖尿病). And the most difficult thing for the young diabetic patients is that many of them don’t have a clear idea when they need to take insulin(a drug used in treating diabetes).The parents of one Long Island boy found the perfect solution—Hero, a specially trained dog that can discover when a diabetic is in trouble and find help.
Johnny Pion, eight years old, is a poor kid that was told he was a diabetic in 2008. He can’t do without insulin. His blood-sugar levels should be closely checked. He even can’t go out to play without his mom or dad fearing he might need help.
With Hero in her new home, Johnny’s parents may worry a little less. They received the news about Hero on the newspaper. The dog cost around $20,000. With the help of friends and family, the Pions brought Hero home from Warren Retrievers in Virginia. Mary Campbell. Hero’s trainer, said the dog could discover the slightest changes in blood sugar by her sense of smell.“Humans have 5 million smell receptors(感受器)； dogs have 5 billion smell receptors,”she said.
When the dog discovers something’s wrong, she’ll rub(蹭)her head against Johnny’s legs. If he doesn’t answer her, Hero knows to look for Johnny’s mom and dad. Hero even could ring up 911.
On their first night, Johnny’s was comfortably sleeping in his own bed with Hero and not with his parents for the first time. Night time is very important because blood sugar goes unchecked while sleeping. Now Hero is a round-the-clock nurse.
Young people with diabetes have difficulty      .

A．telling when they need to take medicine

B．finding what is he best medicine for them

C．remembering the names of their medicine

D．knowing how to keep healthy and live a longer life

Hero can help Johnny because she      .

A．cost around $20,000

B．never sleeps during the night

C．has 5 million smell receptors

D．can discover the changes of blood sugar

What can we learn from the passage?

A．Hero can telephone her owners for help.

B．Hero is helpful for the family.

C．The Pions paid for the dog by using donations.

D．The Pions provided special food for the dog.

After Johnny Pions got ill, he had to      .

A．carry insulin every day

B．go to hospital very often

C．sleep under the care of others

D．live with his family doctor