1.三倍 triple
　　他使自己的收入增至三倍。
　　He tripled his income.

　　2.三只手 pickpocket
　　车上穿黑衣服的男人是个三只手。
　　The man in black on the bus is a pickpocket.

　　3.三级风 gentle breeze
　　我认为三级风不强烈，反倒很舒服。
　　Gentle breeze is not strong， but very comfortable， I think.

　　4.三角裤 brief
　　我的平角裤小了，想买几条三角裤。
　　My pants are small now， I want to buy some brief.

　　5. 三长两短 unexpected misfortune
　　我的儿子要是有个三长两短，我就不想活了。
　　Any unexpected misfortune happened to my son， I would not live any longer.

　　6.三次方程 cubic equation
　　我必须解出这道三次方程。
　　I must work out the cubic equation.

　　7.三番五次 again and again
　　这个话题我已经三番五次地说过，我不想再说了。
　　I have talked about the topic again and again， so I don‘t want to speak it any more.

　　8.三令五申 repeated injunctions
　　你们必须都知道，三令五申的法令要遵守。
　　All of you must know that the repeated injunctions must be obeyed.

　　9.三心二意 be of two minds
　　今天早上吉姆上课时三心二意，心不在焉。
　　Jim was of two minds in class this morning.

　　10.三言两语 in a few words
　　李先生三言两语解释了整个事件，记者对他的回答不满意。
　　Mr. Lee explained the whole thing in a few words， and reporters were not satisfied with his answer.

　　11.三角恋爱 love triangle
　　汤姆和玛丽正处于三角恋爱之中，他们各自有家，这很危险。
　　Tom and Mary are in love triangle， and they have their own families. It‘s very dangerous.

　　12.三下五除二 meat and quick
　　干的漂亮，这项工作三下五除二就完成了。
　　Well done， the job was finished in neat and quick.

　　13.三思而后行 look before you leap
　　不管你想做什么事，请三思而后行。
　　No matter what you want to do， please look before you leap.

　　14.三点式游泳衣 bikini suit
　　玛丽喜欢穿三点式游泳衣游泳。
　　Mary likes swimming in bikini suit.

　　15.三寸不烂之舌 have a silver tongue
　　汤姆会用他三寸不烂之舌说服约翰放弃他的疯狂计划。
　　Tom has a silver tongue， and he can persuade John to give up his crazy plan.