UC知道Three questions.
来源：百度知道 编辑：UC知道 时间：2024/05/22 19:38:52
1、Henry must have stayed up last night, ____ he looks so tired and sleepy.
A. for B. as C. though D. since
2、You must always look carefully ______ you cross the road.
答案是before，我理解。可是不知道为什么觉得when也对。如何克服不去用when呢？
3、They were doing their homework when the telephone rang.
可以写成：They did their homework when the telephone was ringing. 吗？总是会弄不清楚到底是应该在从句还是主句里用过去进行时。
希望得到详细解答~
A. for B. as C. though D. since
2、You must always look carefully ______ you cross the road.
答案是before，我理解。可是不知道为什么觉得when也对。如何克服不去用when呢？
3、They were doing their homework when the telephone rang.
可以写成：They did their homework when the telephone was ringing. 吗？总是会弄不清楚到底是应该在从句还是主句里用过去进行时。
希望得到详细解答~
1.选a
for可以引导原因,相当于because.其他三项都有转折的意思,与原句意思不符
2.因为look是一个瞬间动词,而when表达的是一个持续性的动作概念,所以用before更好些
3.从句两种都可以用,主句必须得是were doing their homework,要突出强调当从句动作发生的时候,主句的动作是正在发生的
1.B
1.B,AS有因为的意思
2.我认为都可以.一个是过马路前先仔细看,一个是过的时候,看理解了.这里或许更强调过马路前就要仔细了
3.不可以,如果写成when the telephone was ringing.前面应该是they were doing their homework,保持一致的时态
1.A
2.when 也可以,只是没有before好,before强调在动作发生之前,而when是在动作发生同时,用在这里勉强可以.
3.不能改,主句用过去进行时,从句用一般过去式.多说一 句,主句的动作是发生在从句动作发生中间.
第一题我觉得应该选C，其他三个都是因为的意思;
第二题你是要在过马路前看有没有车，当然应该用before,难道你是过的时候才看吗；
第三题你用进行时，然后再用when表示你正在干什么事的时候，发生了什么事情，顺便加一句，while后面用进行时。