1 . I find ________ difficult to catch up with others. (用适当的词填空)

2 . _________is said that there are millions of children working on chocolate farms in Africa alone. (用适当的词填空)

3 . ________ is my duty to do something for students in poor areas. （用适当的词填空）

4 . As a foreign student, Tom found __________difficult to write in Chinese. (用适当的词填空)

6 . It was April 29, 2011 ________Prince William and Kate Middleton walked into the palace hall of the wedding ceremony. （用适当的词填空）

7 . It suddenly occurred to him _____ he had left his keys in the office.

8 . It's good ________ (help) others when they are in trouble.

9 . Personally, I don’t think it worthwhile for them ________ (spend)all the savings on this trip.

10 . I’d appreciate ______ if my cellphone could be fixed as soon as possible.