1. We didn't go to South Hill for a trip because the rain yesterday.                       __________
2. I wonder when will we start the charity walk.                                               __________
3. Have you listened to the radio? Will it be cold or rain tomorrow?                     __________
4. The story took place at the first of last term.                                                 __________
5. Fund-raising events are meaningful to organize them.                                     __________
6. That is difficult for me to catch up with my classmates.                                 __________
7. Because Kitty will go back to America so we plan the activity of "A day out".   __________
8. I think that is useful to learn a second language.                                            __________
9. You'd better to save money and help poor classmates.                                   __________
10. Unluckly, he didn't become healthy in the end.                                            __________

A. why                          
B. what  
C. that                          
D. whether