III. Choose the best answer to complete these following sentences. 
 
1. My classmates suggested playing chess but I prefer ________ hike and seek.
 A. playing    B. play     C. played     D. to playing 
 
2. You don't like English food. What about ________Chinese food? 
A. to eat     B. eat     C. eating     D.ate 
 
3. I think we should ________ up our neighborhood. 
A.  to clean      B.clean     C.cleaning  D. cleaned 
 
4. Our teacher suggests ____a meeting to discuss about the solution to keep our environment clean. 
A.  to hold    B.hold     C.holding  D. held 
 
5. Her former leader suggests that she should ________ harder to break her past records. 
A. to train      B.train      C.training  D. trained 
 
6. The children volunteer to clean up the local park ____ there are lot of used cans and trash there.
 A. but      B.because     C.and  D. so 
 
7. Her mother took her to the zoo ________ it owed her some rare animals. 
A.  but      B.because     C.and  D. so 
 
8. The "Green Sunday" was short: ________, the students enjoyed it very much. 
A. but      B.because      C.however     D,.although 
 
9. Hoa missed the bus this morning, ________ she went to school late.
A. but    B. so      C.however  D. and 
 
10. Dioxins are dangerous chemicals________ they can cause cancer and birth defects.
 A. but      B.however      C.because     D.therefore