1 . ________ with international experts with the aim of encouraging further archaeological research, Fan Jinshi worked tirelessly ________ that Dunhuang was protected.

A．Cooperating; to make sure	B．To cooperate; to make sure
C．Cooperating; making sure	D．To cooperate; making sure

2 . ______ to the discovery of black holes, Stephen Hawking is one of the most ______ scientists who have changed the way human understand the universe.

A．Devoted; admired	B．Devoted; admiring
C．Devoting; admired	D．Devoting; admiring

3 . Both moral virtue and intellectual virtue are worthwhile human pursuits, but some scholars _________ the former as a universal need for a healthy civilization.

A．advance

B．empathize

C．elevate

D．approve

4 . The Smiths would like to ________ on a trip to Beijing, but it was called off because of their father’s illness.

A．go

B．have gone

C．going

D．having gone