October 21，2013was an unforgettable day．Harbin had to close roads and schools，and stopped hundreds of flights from its airport，because the air pollution was so bad there．

News reports said the smog （雾霾） was so thick that people couldn't see more than 10or 20meters in front of them．The city's website said："You can't see your own fingers in front of you．"The local people said there was a"burning"smell in the air．Many people covered their noses and mouths with scarves．

The pollution was caused for the following reasons：farmers burnt off corn stalks （称）；the people burnt coal （煤） for heating and winds were low，which allowed the smoke to remain over the city．

Harbin has a population of more than 10million people．It lies in northeastern China，where cold winter weather can last six months．The main fuel （燃料）there is coal，because it is cheaper than other types of fuel．

Air pollution from burning coal can cause health problem like heart disease．During the smog days in Harbin，the number of people taken to the hospital with breathing problems was 30% higher than usual．

The local government is trying to use less coal by adding much better roofs and windows to building to cut heating needs．It has also used cleaner fuel for cars and factories．

66．Which of the following sentence is the best for the blank （ 横线）in paragraph 2？ 　　

A．	They could not even see the person standing next to them．
B．	They lived a healthy and happy life．
C．	They got up a little earlier than before to enjoy fresh air．
D．	They could hear each other clearly．

67．What is talked about in paragraph 3？ 　　

A．	The people of the city．
B．	The food of the city．
C．	The reason for the pollution．
D．	The life of the farmers．

68．Coal is the main fuel in Harbin，because 　　

A．	coal is richer in Harbin．
B．	coal is cheaper in Harbin．
C．	coal is greener in Harbin．
D．	coal is clean in Harbin．

69．How does the local government cut heating needs？ 　　

A．	By using cleaner fuel for cars and factories．
B．	By burning off corn stalks and coal．
C．	By stopping hundreds of flights from its airport．
D．	By add much better roofs and windows to buildings．

70．What's the best title （标题） of the passage？ 　　

A．	The air pollution in Harbin．
B．	The water pollution in Harbin．
C．	The noise pollution in Harbin．
D．	The land pollution in Harbin．