第二部分：英语知识运用(共两节。满分45分)
第一节：语法和词汇知识(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. As the spokeswoman said, ______ we should take action against them depends on what they will do.
A. why B. if C. whether D. that
22. David was always ______ his best in any danger, but at that moment he froze.
A. at B. in C. for D. on
23. ______ there was no conclusive evidence, most people thought he was guilty.
A. Since B. While C. When D. However
24. — Have our travel plans been decided?
— No, still ______.
A. out of order B. up in the air C. in the case D. in the way
25. Dad decided to build a small tool room with a lock, ______ he would keep his best tools so my brother couldn’t reach them.
