2. It dawned on me that I had left my purse at home when I was about to pay my phone bill. （忘記發生在was about to pay之前所以用過去完成時）
3. While I was in London, I went to the British Museum several times. （介詞during不能引導從句所以改為從屬連詞while）
4. Times have changed, and we should change, too. (times為時代)
5. I thought I heard someone come in while I was surfing the Internet.
6. He sent me a text message to remind me that the composition was due the next day.
7. The world is changing so fast that we can hardly keep up with the pace of change.(so ,,that如此，，以至於)
8. My yesterday's supper consisted of whole wheat noodles, cabbages and chicken. (cabbage是可數名詞要加復數)
9. The farmer said that he had four children to take care of. （take care of是固定短語）
10. This is an area which the United States regards as its backyard。（定語從句的先行詞在從句中不能重復所以沒有代詞it）