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. It’s hard to imagine _____ in a place _____ there is no water.
A. living, that B. to live, where
C. to be living, which D. living, where
22. She waved her hands in order to make herself _____ .
A. to be seen B. see C. to see D. seen
