maybe it is ____they have a harder life.A.what B.how C.why D.because

问题描述:

maybe it is ____they have a harder life.A.what B.how C.why D.because
怎么选D呢?我选的C,但老师说D符合意思,是不是跟语法神马的有关……

看意思吧,语法的话两个都是表语从句,做前面is的表语.
it is why... 这是为什么... /这就是...的原因, 说明前面的句子是这个句子的原因
如: Tom was ill. It is why he didn't come yesterday.
汤姆生病了.这是他昨天没来的原因.(生病是没来的原因)
it is because... 这是因为...说明前面的句子是这个句子的结果
如:You are fat. it is because you eat too much.
你很胖.这是因为你吃太多了. (胖的原因是吃太多)
你这个句子不完整,要看前面的那个句子和这个句子是什么关系,如果是原因就是why,结果就用because