21. make the bed铺床
You are old enough to make the beds by yourself.
22. beg one's pardon请某人再说一遍
Sorry I didn't catch it. I beg your pardon.
23. begin… with以……开始
The party began with a cheerful song.
24. believe in信仰
In western countries, many people believe in God.
25. belong to属于
That Taiwan belongs to China should be unquestionable.
26. do one's best尽最大的努力
If you have done your best, then there's nothing to regret.
27. had better最好
You had better stop smoking.
28. blow away吹走
The wind blew the heat away.
29. take a boat乘船
I took a boat to go to the island in the center of the lake.
30. be born出生
He was born in a wealthy family.
31. break away from从……脱离，断绝关系
We won't say "Yes" to anyone's breaking away from our country.
Can't you break away from old habits?
32. break down（指计划、打算）破灭；（机器）坏了；（身体状况）变差
Our plans have broken down.
Negotiations between the two countries have broken down.
The engine broke down.
His health broke down after the death of his wife.
Sugar and starch are broken down in the stomach.
33. break into破门而入
His house was broken into last week.
34. break off 从中间打断
He broke off in the middle of a sentence.
Let's break off for an hour and have some tea.
The mast broke off.
35. break out（指战争、灾难、争吵等）突然爆发
A fire broke out during the night.
The quarrel broke out afresh.
36. break the rules违反规则
Everyone in the group mustn't break the rules.
37. break up击碎、驱散 终止   结束 分裂   分开 分手放学
The ship was breaking up on the rocks.
The gathering broke up in disorder.
The police broke up the crowd.
38. hold one's breath屏住呼吸
He held his breath and sneaked into his room.
39. bring down击落、打倒
A moment ago, we brought down a hostile aircraft.
We should bring down the tyrant.
40. bring in赚得、赢得（利润） 
His farms bring (him) in $20000 a year.
The program brings in a new fashion.