第二部分：英语知识运用(共两节, 满分45分)
第一节: 单项填空(共15小题；每小题1分, 满分15分)
从A、B、C、D四个选项中, 选出可以填入空白处的最佳选项
21. —Thanks for helping me with this difficult maths problem.
—____. That’s what a close friend should do.
A. Nothing serious B. All right C. Never mind D. Forget it.
22. Rainforests __ and burnt at such a speed that they will disappear from the earth in the near future .
A. were cut B. are cut C. has been cut D. are being cut
