Mark was a student at this university fr
问题:
Mark was a student at this university from 1999 to 2003, ____ , he studied very hard and was made Chairman of the Students' Union.
A.during which time
B.for which time
C.during whose time
D.by that time
Mark was a student at this university from 1999 to 2003, ____ , he studied very hard and was made Chairman of the Students' Union.
A.during which time
B.for which time
C.during whose time
D.by that time