All ____is needed is access to the internet with a high-speed cable connection A which B what C tha
问题描述：
All ____is needed is access to the internet with a high-speed cable connection A which B what C tha
答案选C为什么不选B请说明理由
答
All ____is needed 是整句的主语,相当于一个名词,中心词是all,后面____is needed 是all的定语从句,定语从句缺少主语,那么关系代词必须是指物的,还必须能做主语,所以只能从A和C中选择,因为B不是关系代词!
当先行词指物,但是是不定代词时,只能用that,不用which.
如果一定想用what, 那么应该写成：
What is needed is access to the internet with a high-speed cable connection
其中What is needed是主语从句,What是该主语从句中的主语.
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