1. I'm sorry, _________ I won't be able to come tonight.
A. for B. and C. but D. then
【陷阱】容易误选A，因为空格后的句子是用以说明 I'm sorry 的原因的，所以便想当然地认为要选for来表示原因。
【分析】事实上，I'm sorry 后习惯上不接表示原因的连词for后习惯上不接表示原因的连词，而接表示转折的连词but（也可省略 but），用以委婉地提出一个使对方不快的事实。又如：
Oh, sorry, but she's out. 哦，不好意思，她出去了。
I'm sorry, but I have to disagree. 对不起，我不敢苟同。
I'm sorry, but I have already had another appointment. 对不起，我已经有约会了。
注：I'm sorry 后虽然不能接表原因的连词for，但却可接介词 for。如：
I'm sorry for shouting at you. 对不起冲你嚷嚷了。
I am sorry for what I said to you. 我后悔不该对你讲那些话。
2. The point is not who said the words, _________ they are true or not.
A. but whether B. and whether C. but how D. and how
【陷阱】几个干扰项均有可能误选。
【分析】最佳答案为A。此题涉及两个搭配：一是 not ... but ...（不是……而是……），二是 whether ... or not (是否)。请看类例：
He was not an actor, who often appeared on stage, _________ a writer, writing stories.
A. but B. and C. then D. so
答案选A，主要考查 not ... but ... 结构。
3. Just because they make more money than I do, _________ they seem to look down on me.
A. so B. and C. but D. 不填
【陷阱】但容易误选A，将汉语的"因为……所以……"直译为 because ... so ...。