B1: Read the passage and choose the best answer A,B,C or D each question below
i often hear or read about " natural disasters" - the eruption of Mount St. Helen , a volcano in the state of Washington , Hurricane Andrew in Florida , the floods in the Midwest America, terrible earthquakes all over the world , huge fires , and so on . But I'll never forget my first personal experience with the strangeness of nature - the London Killer Fog in 1952 . It began on Thursday , December 4, when a high- pressure system of warm air covered southern England. With the freezing-cold air below, heavy fog formed. Pollution from factories, cars and coal stoves mixed with the fog. The humidity was terribly high. There was no breeze at all. Traffic such as cars, trains.boats stopped. People couldn't see very well, and some walked onto the railroad tracks or into the river. It was hard to breathe, and many people got sick. Finally, on Tuesday, December 9, the wind came and the fog went away. But after that, even more people got sick. Many of them died. 
1) Which " natural disaster" is NOT mentioned in the passage ?
 A: a hurricane                 B: a flood                       C: a tornado
2) What is the write's unforgettable personal experience? 
 A: the London Killer                     B: the heavy fog in london in 1952                          C: a high-pressure system
3) How long did the " London Killer Fog" last?
 A: for four days                         B: for five days                            C: for six days
4) What didn't happen during the time of the "london Killer Fog"?
  A: heavy rain                    B: humidity                       C: heavy fog
5) Why did the traffic stop?
  A: Because of the windy weather                  B: Because of the humid weather                   C: Because of the heavy fog