此處填 ：to do
比較以下結(jié)構(gòu)：can’t help to do sth = 不能幫助做某事
can’t help doing sth = 禁不住做某事,情不自禁地做某事
請看例句：I can’t help to do it.我不能幫忙做這事.He couldn’t help to wash the clothes.我不能幫忙洗衣服.She couldn’t help smiling.她禁不住笑了起來.She couldn’t help envying Helen.她不由得 不妒忌海倫.We cannot help being impressed by their zeal.我們不由得不被他們的熱情感動.英語有時還可說can’t help somebody doing something不能使某人不做某事.如：I couldn’t help him saying that.我不能讓他不這樣說.We couldn’t help them seeing us.我們無法讓他們不看到我們.She could not help the tears of rage rolling down her face.她止不住她憤怒的眼淚順著面頰流下來.
又如下面一題,答案也是 B：She can’t help _________ the house because she’s busy making a cake.A.cleaning B.to clean C.cleaned D.being cleaned
再請看以下試題：
While shopping,people sometimes can’t help _________ into buying something they don’t really need.
A.to persuade B.persuading C.being persuaded D.be persuaded
此題應選C,句中的 can’t help 意為“禁不住”（注意根據(jù)句意用被動形式）.