let alone后面跟do和doing的區(qū)別

　　let alone后面結(jié)構(gòu)主要取決于其前面對(duì)比內(nèi)容結(jié)構(gòu),即要與其前面結(jié)構(gòu)保持一致!

　　例如:

　　1.Protecting the air,let alone improving it,is a challenge.

　　別說(shuō)要改善空氣了,現(xiàn)在就是保護(hù)它也很難.

　　2.The central government has struggled to count this debt,let alone control it.

　　對(duì)此中央政府連貸款金額都無(wú)法匯總,更別說(shuō)對(duì)貸款進(jìn)行調(diào)控.

　　3.Tourists need have no truck with maldivian culture or currency,let alone its politics.

　　游客們不必與馬爾代夫的文化、貨幣打交道,更別說(shuō)政治了.