英语~单选~~HELP~

题目

英语~单选~~HELP~
（请讲的通俗点~我笨.）问题1:It's___he often fails in exams___makes his parents worried about him.答案是C:that;that 我的选是A:what;that 问题2：___your works with mine and you'll find many differences. A.comparing B.compare C.to compare D.if you compare
(我总是在非谓语动词上错,像单选,我总不知道该填现在还是过去分词. 该怎么区分）请通俗点.谢谢
关于2，用祈使句前后就一致了？再是省略哪里了~麻烦补全下；谢谢你，前面的我懂了。。。

答案

1选that;that那个选项.第一个that是用于引导表语从句(be+that+句子,少这个空成一句话的就用that,否则就用what);而第二个that是强调句型(It is/was+要强调的部分+that+剩下句子成分),是固定用法,这句话就相当于强调是...