- A.the greenhouse effect
 - B.the burning of fossil fuels
 - C.the potential effect of air pollution
 - D.the likelihood of a new ice age
 
- A.shares the same view with the scientists
 - B.is uncertain of its occurrence
 - C.rejects it as being ungrounded
 - D.thinks that it will destroy the world soon
 
- A.raising the wodd’s temperature only a few degrees w.ould not do much.harm to life on earth
 - B.lowering the world’s temperature merely a few degrees would lead many major farming areas to disaster
 - C.almost no temperature variations have occurred over the past decade
 - D.the world’s temperature will remain constant in the years to come
 
- A.slip into
 - B.make up for
 - C.set up
 - D.catch up with
 
- A.is always
 - B.hopes for a change
 - C.never stops changing
 - D.will live a different life
 
- As Dointed out at the beginning of the passage,people used to think that air pollution__________ .
 - A.caused widespread damage in the countryside
 - B.affected the entire eastern half of the United States
 - C.had a damaging effect on health
 - D.existed merely in urban and industries areas
 
- A.man has been growing taller over the past 500 years
 - B.man has got stronger eyes than he ever had
 - C.man’s hair is getting thinner and thinner
 - D.man’s limbs are getting weaker because he tends to make less use of them
 
- A.he will use of only about 20%of the brain’S capacity
 - B.the other 80%of his brain will grow in due time.
 - C.he had rather narrow forehead a few hundred years ago
 - D.he will have to use his brain more and more as time goes on
 
- A.have smaller eyes
 - B.see better
 - C.have larger eyes
 - D.gave to wear better glasses
 
我



