1. (2022·衡阳) 阅读下面的短文，从每题所给的 A、B、C 三个选项中选出最佳选项回答问题或完成句子。

A big sandstorm hit northern China several months ago. It covered many cities with thick clouds of yellow dust(尘土).

The storm, which came from Mongolia, was the largest sandstorm in China in the past 10 years Many flights and classes were canceled because the visibility(能见度)was lower than 500 meters.

The storm was the result of warm and dry weather in the area, together with the strong winds from Mongolia. "There has been little rainfall so far this spring and the temperature is rising. So now it is a worrying time for sandstorms. "said an expert from Beijing.

In recent years, sandstorms haven't been as common in northern China as before. The land with desertification(沙漠化) has been falling by 7, 585 km per year in China, and the area of sandy land has been decreasing by 1. 284 km' a year. This is thanks to China's Three-North Shelter Forest Program(TNSFP 三北防护林工程)which started in the 1970s. Millions of trees have been planted in northern China to prevent sandstorms and protect the environment.

Besides, China has a color-graded weather warning system(预警系统)for sandstorms, with red meaning the most serious, followed by orange and yellow. Therefore, people would have time to get prepared for the sandstorm.

Sandstorm       ＜ 1 kilometer

Severe sandstorm       ＜  500 kilometers

Super severe sandstorm       ＜  50 meters

1. （1） What caused the sandstorm from Mongolia?

   A . Cold and wet weather together with the strong winds. B . Warm, dry weather and the strong winds. C . Warm, wet weather and the strong winds.
3. （2） The underlined word "decreasing" means"_____________".

   A . going up B . putting down C . going down
5. （3） When did TNSFP start?

   A . In the 1970s. B . In the 1980s. C . In the 1960s.
7. （4） If the visibility in your city is 700 meters, what color will the warning be?

   A . Red. B . Orange. C . Yellow
9. （5） What can we infer(推断)from the passage?

   A . We have taken some actions to prevent sandstorms. B . Sandstorms have never changed. C . The weather is getting worse and worse.