1 . Have you ever noticed the Mu Us Desert (毛乌素沙漠) in the northwest when you read a map of China? If you haven’t, then you probably never will. That’s _______ the desert is disappearing.

You might wonder: Why is this happening? Who is the “killer”? Well, it is the _______ of years of efforts in tree planting. In China, the Mu Us used to be one of the largest deserts in size. Sandstorms were common in northern Shanxi. Lots of people had to leave their homes. The fight against desertification (沙漠化) began in the1970s. A team planned to plant trees in the desert. It once took them a whole afternoon to plant trees under a burning sun. That night, however, a strong wind blew away all the young trees. Crying was _______. The next day, the team replanted all the trees.

In Yulin, there are many other fighters. One of them is Guo Chengwang. He started to plant trees in his village when encouraged by the government in 1985. Guo is now in his nineties. His children, grandchildren and great-grandchildren have _______ the job. The family has turned 30 km² of desert into woods.

These trees have made a big difference. In Yulin, the number of sandy days has _______ from 100 in 2000 to 10 now. With the joined and continuing efforts, the Mu Us Desert will be gone. Our motherland will become greener and lovelier.