4. keep sb. from doing sth. 阻止……做……
= stop sb. ( from ) doing sth.
= prevent sb. ( from ) doing sth.
3. know about …… 了解……
2. hear from sb. 听到/收到……的音讯/来信
1. hear of sth. 听说……
19. do sth. as … as possible to do sth. 为了做……而尽可能……地做……
Lesson 42
18. keep sth. straight 把……扶直
17. tie sth. to sth. 把……绑到……上去
16. put sth. back 把……放回去
15. push sth. down 把某物往下按/踩
14. so that … 以便……