this factory is quite different from______before

题目

this factory is quite different from______before
为什么要用what it was,而不是that it was 或者which it was 呢
2）we were all surprised when he made it clear that he would leave office soon.
其中的when he made it clear怎么解释,在句中的成分是什么
3）followed by some officials,Napoleon inspected his army
这句前半句是什么状语,哪是主句哪是从句,前半句是不是句省略句啊
4）as is expected ,all the students in our class have passed the exam
前半句是什么状语从句啊,是不是省略句啊,省略了什么.As在这里为什么不能作原因的解释,能作为原因状语来解释吗
5）he's somewhere in his fifties 什么意思啊

答案

用what it was 是因为在从句中是充当主语的
时间状语从句,that后面引导的是it的真正内容,这句话解释为我们在他把那么快能离开办公室这件事情解释清楚时我们都很惊讶