例句： Their opinions on art are simply for the birds.
他们对艺术的见解真是荒唐可笑。
beat it 叫人 " 走开 " 的 口语 ，和 "Be off! 差不多，不过比后者更流行。
例句： He kept on bothering me, so I told him to beat it.
他不停地烦我，因此我叫他走开。

beat ones brains (out) 　指做事困难， " 伤透了脑筋 "
例句： I beat my brains (out) to get a job.
为了找寻工作，我伤透了脑筋。
beat sb to the draw 　抢先某人行动

例句： Mary wanted to buy that painting by Picasso, but another millionaire beat her to the draw.
玛丽想买毕加索的那幅画，不过另一个百万富翁捷足先登了。
beat someone by miles 　远强于某人
例句： When it comes to fishing, I beat him by miles.
讲到钓鱼，我比他棒得多。

beef 口语上常用来指 " 抱怨 " 或 " 发牢骚 " ;作动词时后面跟 about.
例句： Tell me what's your beef­
你抱怨什么­

before you know it 口语为 " 很快 " 。
例句： I come back before you know it.来源：考试大
我很快就会回来。

behave yourself 　劝人要有礼貌和行为检点，意思相同的口语还有 "Watch you manner.""Watch your P's and Q's". 和 "Don't get fresh."
例句： Please behave yourself before the guests.
在宾客之前你检点一些。

behind bars 　坐牢
例句： The judge will put him behind bars for at least two years. 法官最低限度也会判他坐两年牢。
behind the scenes ( behind the curtain )　 幕后

例句： He is the man behind the scenes.
他是幕后人物。
between ourselves 秘密地说

例句： Between ourselves, there are no secrets.
咱们私下说说，没什么秘密。
beyond the seas 在国外，在海外

例句： He had a good time when he was beyond the seas.
他在国外时曾过得很快活。
butt in 　插手，介入

例句： Pardon me for butting in on your conversation, but this is important.
请原谅我打断了你们的谈话，不过这件事非常重要。
by and large 　大体上，总的看来

例句： I cannot totally take your point ， but by and large I think yours is reasonable.
我不能完全同意你的观点，但大体上你的观点是有道理的。