搭配辨析set off 与setout，set about
．polonium is used to set off a nuclear bomb．钋用来引爆核弹。
(1)本句中set off 意思是"使……爆炸"，及物性短浯动词：e．g．
They set off the fireworks as soon as it got dark．天一黑他们就放焰火(烟花)。
(2)set off 还可指"出发，动身"，不及物性短语动词。e．g．
They set off in search of the lost child．他们出发去寻找那个丢失的孩子。
(3)set off 还可意为"引起，触发"，及物性短语动词。e．g．
①That strike set off a series of strikes throughout the country．那次罢工引发了全国一系列的罢工。
②A letter from home set off an attack of homesickness．一封家书触发了他的思乡病的发作。
(4)set off 还可指"使某人突然产生某种活动"，其后往往接v.-ing，即set s.b．off doing sth．e.g.
Whatever you say will set her off crying.不管你说什么都会使她哭泣。
(5)set off还可指"衬托，使更明显"。e．g．
This gold frame sets off your painting well．这金色的框架把你的画衬托得非常好看。
搭配辨析set off 与setout，set about
(1)set out也可意为"出发，动身"，用法与set off同，不及物性短语动词。e.g.
They set out／off on a sightseeing tour．他们动身出去观光旅行。
(2)set out还可指"开始着手，做某事"，后接动词不定式。e．g.
We set out to paint the whole house but finished only the front part．我们为油漆整座房子开始干起来，但只完成了前面部分。
(3)set out可指"陈列，摆出，安排"，及物性短语动词。e．g.
①Set out the chairs for the meeting in rows of ten．摆好开会的坐椅，每排十张。
②The meal was set out on a long table．饭菜摆在一张长桌子上。
(4)set out还可指"表明，陈述，阐述(事实、理由等)"。e．g.
The reasons for my decision are set out in my report．我作出决定的理由在我的报告中作了阐述。
(5)set about意为"开始做或处理，着手"，其后接名词或v.-ing，即set about + sth．／doing sth．e.g.
① The sooner we set about it the sooner we'll finish．我们越早开始就可以越早完成这件工作。
②We set about cleaning up mess．我们开始把乱七八糟的东西打扫干净。
(6)set about还可指"攻击"，及物性短语动词。e．g.
Our dog set about the postman．我们的狗追着要咬邮递员