阅读短文选择正确答案 并找出关键词语 、句子Milan,the second largest city of Italy,has won an undesirable world record.Of the 54 big cities studied by the World Health Organization and the United Nations,Milan was considered to have the worst air pollution.According to these two 10-year studies,the level of air pollution in Milan is twice as high as the levels in Paris and Beijing and three times those in Tokyo and London,and four times that in New York.The reason for Mila

阅读短文选择正确答案 并找出关键词语 、句子
Milan,the second largest city of Italy,has won an undesirable world record.Of the 54 big cities studied by the World Health Organization and the United Nations,Milan was considered to have the worst air pollution.
According to these two 10-year studies,the level of air pollution in Milan is twice as high as the levels in Paris and Beijing and three times those in Tokyo and London,and four times that in New York.The reason for Milan’s bad pollution,to some experts,is that the city lies in a valley that holds back the poisonous( 有毒的 ) gases.
Though Milan has taken some measures to lower the level of pollution,the situation is still worrying.People joke to each other,“If you’re traveling to Milan,be sure to bring your gas mask(面具).”
In order to reduce the use if private cars in 1979,the Milan began an interesting experiment:Passengers in the city buses didn’t have to pay for their tickets.
1.Which is NOT mentioned in the passage?
A.The reason for the air pollution in Milan.
B.Experts thought that the air in Milan was badly polluted.
C.Milan’s water is regarded to be worst polluted.
D.The measures taken by Milan to reduce the air pollution.
2.Which of the following cities keeps the lowest level of air pollution?
A.London B.Tokyo C.Paris D.New York
3.Why is the air pollution in Milan so serious?
A.Because the city lies in a place where it is difficult for polluted air to move
away.
B.Because too many cars are being driven in the city.
C.Because the city lies in a place where there are some mountains near it.
D.Because Milan has taken some worrying measures
4.According to the passage,which of the following is TRUE?
A.Milan has taken some measures and the air pollution is being reduced.
B.Milan has taken some measures,but the air pollution is still troublesome.
C.Milan has taken no measures so far to lower the level of pollution.
D.Milan has taken every step to reduce the air pollution.
5.The government of Milan encouraged the people to take city buses for free in order to ______.
A.have a safer transport B.stop the air pollution completely
C.increase the income of the bus company D.reduce the pollution made by cars
错在在哪啊？