1 . Choose proper phrases and use their correct forms to complete the sentences.

keep one’s balance, struggle with, fall off

1. Look out! You would _________ the ladder.
2. The immigrants have to _________ an unfamiliar language and new customs.
3. When you first learn to ride a bike, you often need stabilisers to help you _________.

2 . 根据句意，选择单词或短语并以其适当形式填空。

lose track of, turn up, cut down, lead to, from time to time, concentrate on, recover from, up to, fall off, after all

1. You should forgive him for his forgetfulness; ________， he is over seventy.
2. Young children can’t ________ one activity for a very long time.
3. He promised to come, but so far he has not ________．
4. You won’t ________ the stepladder; I’ll hold it for you.
5. In the past ten years, a lot of trees have been ________ in the mountain.
6. Smoking too much will ________ lung cancer.
7. I can’t agree more. We need to get away from work ________．
8. She returned to her hometown to ________ an illness.
9. We could go now or later—it’s ________ you.
10. Tom’s work was so interesting that he ________ the time.