【正文】
all over the world. Great Green Walls will make the world better. 根據(jù)短文內(nèi)容,選擇正確答案。 1. In 1620, about ______ the USA was covered by forests. A. a third B. half C. two thirds D. a fourth 2. A lot of good land has gone with ______. A. sand B. water C. wind D. forests 3. The Great Green Wall in China is ______ long. A. 7,000 kilometers B. 1,700 kilometers C. 7,000 meters D. 400 kilometers 4. Trees must be grown in ______. A. China B. the USA C. some countries D. every part of the world 5. ______ will make the world better. A. The Great Wall B. Tall buildings C. Great Green Walls D. Flowers and grass B The students were having their chemistry(化學(xué)) class. Miss Li was telling the children what water was like. After that, she asked her students, “What’s water?”No one spoke for a few minutes . Miss Li asked again,“Why don’t you answer my question ? Didn’t I tell you what water is like? ” Just then a boy put up his hand and said, “Miss Li , you told us that water has no colour and no smell. But where to find such kind of water?The water in the river behind my house is always black and it has a