1 . ______ (replace) the flat tyre with a new one and move on. （所给词的适当形式填空）

2 . Tears came to my eyes as I realized ______ a fool I had been to judge Jim’s father as a failure. （用适当的词填空）

3 . ________ you ________ (brush ) your teeth every day? (所给词的适当形式填空)

4 . ________(sharp) up your public speaking skills, so that you can share your book with relevant audiences. (用所给词的适当形式填空)

5 . Keep these tips in mind ___________you’ll learn English well. （用适当的词填空）

6 . ________(concentration) on your study, and you will make greater progress.

7 . ________ (base) an important decision more on reason than on emotion, or you will regret it soon. （所给词的适当形式填空）

9 . We ________(not) get homesick when we get back home. （所给词的适当形式填空）

10 . If we _______ (not, act)now to protect the environment, we’ll live to regret it. (所给词的适当形式填空)