1 . The Students’ Union is like a huge stage, ___________ everyone spares no effort to achieve their dreams. (用适当的词填空)

2 . There are lots of foreigners at the meeting, most of ________ are Americans.（用适当的词填空）

3 . I never forget this summer vacation, ___________I spent the happy days with my friends.

4 . Mr. Smith will move into his new house next Sunday, ________ it will be completely finished.

A．by the time	B．on that time
C．on which	D．by which time

5 . The factory produces half a million pairs of shoes every year, _______80% are sold abroad.

A．of which	B．which of
C．of them	D．of whom

6 . In 1963 the UN set up the World Food Program, one of ________ purposes is to relieve worldwide starvation.

A．which	B．it’s
C．whose	D．whom