6. Our teachers are really ______. They often work in their office far into the night.
A. open-minded B. hard-working C. self-confident D. warm-hearted
7. The windows haven’t cleaned for a long time. They need ______.
A. to clean B. to be cleaned C. cleaning D. B and C
8. I am interested in traveling. It is ______ but ______.
A. interesting; tiring B. interested; tired
C. interesting; tired D. interested; tiring
9. The 2010 Shanghai World Expo is well worth ______.
A. visit B. visited C. to visit D. visiting
