21. Yang Liwei was a student at this flight school from 1983 to 1987,             he studied very hard and was made chairman of the Students’ Union.

A. during which time             B. for which timeª¤     

C. during whose time          D. by that time

22. George Gould, a friend of Carnarvon’s, went to Egypt after hearing of his strange death and visited the tomb, only ______a high fever the next day.