根據(jù)語境的不同，in case既可表示“如果”“萬一”，引導條件狀語從句;也可表示“以防(萬一)”，引導目的狀語從句。下面兩道真題均選in case：

　　1. Leave your key with a neighbor ______ you lock yourself out one day. (北京卷)

　　A. ever since B. even if C. soon after D. in case

　　2. My parents live in a small village. They always keep candles in the house ______ there is a power cut. (重慶卷)

　　A. if B. unless C. in case D. so that

　　【解析】兩道題都選in case，均表示“以防萬一”。

　　二、before引導的狀語從句

　　尤其要注意“it+be+一段時間+before…”這一句型。如：

　　1. The field research will take Joan and Paul about five months; it will be a long time ______ we meet them again. (安徽卷)

　　A. after B. before C. since D. when

　　2. He was told that it would be at least three more months ______ he could recover and return to work. (江西卷)

　　A. when B. before C. since D. that

　　【解析】兩道題均before。第1題涉及的句式為：It will be a long time before…，意思是“要過很久才會……”;第2題涉及的句式為：it was some time before…，意思是“在……之前過了一段時間”，通常可轉譯為“要過一段時間才會……”。

　　三、while引導的狀語從句

　　尤其要注意while表示“盡管”“雖然”時的用法(此時它引導的不是時間狀語從句，而是讓步狀語從句——此用法許多同學并不熟悉，值得特別注意!)。如：

　　______ I really don’t like art, I find his work impressive. (山東卷)

　　A. As B. Since C. If D. While

　　【解析】答案選D。while在此表示“盡管”“雖然”，又如：While the work was difficult, it was interesting. 盡管工作有難度，但很有趣。/While I understand what you say, I can’t agree with you. 雖然我理解你的意思，但我還是不同意。

　　另外，while表示對比的用法也值得注意(此時它表示“而”)。如：

　　The cost of living in Glasgow is among the lowest in Britain, ______ the quality of life is probably one of the highest. (天津卷)

　　A. since B. when C. as D. while

　　四、when引導的狀語從句

　　對于when的用法，同學們最熟悉的是表示“當……的時候”。如：

　　—Where’s that report?

　　—I brought it to you ______ you were in Mr. Black’s office yesterday. (北京卷)

　　A. if B. when C. because D. before

　　【解析】答案選B。將四個選項逐一填入空格處，只有填when時，意思最通順。句意為：當你昨天在布萊克先生辦公室時我就帶給你了。

　　但是when還有一個用法，就是表示“既然”。如：

　　Why do you want a new job ___D___ you’ve got such a good one already?

　　A. that B. where C. which D. when

　　還有一點也需注意，就是when表示“這時(突然)”的用法。如：

　　1. I had just stepped out of the bathroom and was busily drying myself with a towel ___B___ I heard the steps. (湖南卷)

　　A. while B. when C. since D. after

　　2. He was about halfway through his meal ___C___ a familiar voice came to his ears. (遼寧卷)

　　A. why B. where C. when D. while

　　五、unless引導的狀語從句

　　unless的意思是“如果不……”“除非”，對于涉及unless的考題，一般只要能讀懂句意，弄清語境，一般不會有問題。如：

　　1. Most birds find it safe to sleep in the trees, but ______ they have eggs or young chicks, they don’t use a nest. (湖南卷)

　　A. why B. how C. unless D. where

　　2. I won’t call you, ______ something unexpected happens. (全國I)

　　A. unless B. whether C. because D. while

　　【解析】兩道題都選unless，均表示“除非”。

　　六、until引導的狀語從句

　　until的意思是“直到……時”“在……之前”，對于涉及until的考題，一般只要能讀懂句意，弄清語境，一般不會有問題。如：

　　It is difficult for us to learn a lesson in life ___A___ we’ve actually had that lesson. (天津卷)

　　A. until B. after C. since D. when

　　另外，還要注意not…until…這一句式(直到……才)。如：江蘇高考網(wǎng)

　　“You can’t have this football back ___D___ you promise not to kick it at my cat again,” the old man said firmly. (廣東卷)

　　A. because B. since C. when D. until