It was about 600 years ago______the first clock with a face and an hour hand was made.A.that B.until C.before D.when这个题选B.说是强调句.我就想知道为什么不能选D.选D可以是时间状语从句啊
问题描述：
It was about 600 years ago______the first clock with a face and an hour hand was made.
A.that B.until C.before D.when
这个题选B.说是强调句.我就想知道为什么不能选D.选D可以是时间状语从句啊
答
选A，than后面的是个从句，指代的是主句中的it。
变成正常的主谓结构就是：The first clock with a face and an hour hand was made was about 600 years ago.
通常这种正常情况下主语过长的句子会用这种that从句，这样句子不会显得头重脚轻。
答
你不觉得“it was 600 years ago"本身就是一个从句似的句子，然后再加个when感觉就出来了，这不对啊
答
把句中的it was...that去掉,句子不缺任何成分.：the first clock with a face and an hour hand was made about 600 years ago.如果选when,句子不通顺,about 600 years ago.是由介词构成的时间状语,不能构成状语从句...