第二部分: 英语知识运用 (共两节, 满分35分)
第一节：单项选择 (共15小题；每小题1分, 满分15分)
请认真阅读下面各题, 从题中所给的A、B、C、D四个选项中, 选出最佳选项, 并在答题纸上将该项涂黑。
21. Every possible means ________ tried but the problem remains unsolved.
A. has been B. have been C. are D. is
22. ________ the little boy looked after his sick uncle a whole year moved us all.
A. What B. That C. When D. Which
