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，并在答题卡上将该项涂黑。
21. - You’re at ______ liberty
to say whatever you like.
- I think you’re taking ______ risk by investing everything in one company.
A. the; /
B. the; a
C. /; /
D. /; a
22. Yesterday we visited a modern hospital, around _________ some fruit shops.
A. which is B. that is C. which are D. it are
23. When I entered the
room, I found Mary ______ at the desk ______ her homework.
A. sat;
doing B.
sitting; to do
C. seating; to do
D.
seated; doing