二、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）
请从A, B, C, D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该选项的标号涂黑。
21. _____ is acknowledged to us is that Qian Xuesheng _____ great contributions to our country's agriculture.
A. As; has done B. It; does do C. What; did do D. What; did did
22.When her father fell into a serious disease, she would sit before the window with her eyes _____ at the street without thinking anything.
A. stare B. stared C. to stare D. staring
