题目内容：

阅读理解。

Every spring Beijing is choked by huge sandstorms.The sky turns a strange and frightening yellow colour as clouds of sand sweep down from the deserts of Mongolia and north-western China.Strong winds blow up the dust and cover everything in sight—in 2006,a storm dumped 330,000 tonnes of dust on Beijing in one night.

The number of sandstorms has grown alarmingly over the years as the deserts have expanded.This is partly man-made and partly because of climate(气候).Many grasslands have been overgrazed(过度放牧)by sheep and goats,or ploughed up,leaving the soil dangerously exposed.Too much water has been taken out of rivers,and the situation is made worse by increasingly long-lasting droughts that have affected the northern half of China as the climate grows warmer and drier.The result is probably the worst loss of rich land to deserts in the world and a dust bowl of extremely large proportions.The nearest sand dunes to Beijing are now only 70 km away and drifting closer each year.At this rate,the desert will reach the city by 2040,and Beijing could become the world’s first modern city to disappear under sand.To hold back the deserts,a huge programme of forest planting called the Great Green Wall has been under way for over 30 years.The barrier(隔离带)is planned to be 4,500 km long when completed in several decades(十年),but the drought is having a very bad effect on the trees and the deserts carry on growing.

1.All the following are the reasons for the expansion of the deserts EXCEPT    .

A.the soil of the grasslands is exposed

B.too much water in rivers has been used

C.it doesn’t rain for a long time

D.the climate in northern China is colder and drier

2.At what speed do the nearest sand dunes move towards Beijing according to the passage?

A.More than 15 km a year.

B.More than 2 km a month.

C.More than 2 km a year.

D.More than 15 km a month.

3.What is the purpose of the huge programme“the Great Green Wall”?

A.To protect the Great Wall.

B.To plant as many trees as possible along the Great Wall.

C.To stop the deserts from moving towards Beijing.

D.To plant as many trees as possible in Beijing.

4.In which section can this passage most likely be found in a newspaper?

A.Science and technology.

B.Weather.

C.Environment.

D.Health and life.