21.—Do you know Ann Watterson very well?
—Yes, she used to be ______ coach and in ______ charge of our school team.
A. a; the B. the; the C. a; 不填 D.不填; 不填
22. Tom was ______ that he couldn’t understand ______ difficult sentence.
A. so a stupid boy; such B. a so stupid boy; a such
C. so stupid a boy; a such D. so stupid a boy; such a
23. _______ the rain falling so hard, it becomes more and more difficult to carry on the rescue work.
A. Since B. As C. With D. For
