词汇运用：根据所给句子的意义及首字母或中文提示写出正确的单词。
1. It is polite to help those who are in t .
2. There is no d that computers are widely used in all kinds of areas.
3. Trees can p the wind from blowing the earth away .
4. She is w in English, let's try our best to help her improve it.
5. Liuxiang is regarded as our national h .
6. Make sure that all (垃圾) should be put into the dustbin.
7. We should learn a lot and master some (基础的) skills when we are learning.
8. Computers are used in business to place and (删除) orders .
9. When a child makes a little progress in studying , we should (表扬) him for it.
10. What's the (人口) of Laibin City? It's more than 2,450,000.