It is __Tom oftrn fails in maths __makes his mother disappointed.
问题描述：
It is __Tom oftrn fails in maths __makes his mother disappointed.
两个空为什么都填that
答
（It is）thatTom oftrn fails in maths （that ）---强调句式,可省略,便于分析句子结构 makes his mother disappointed.化简 thatTom oftrn fails in maths（主语.为一件事,谓语单数）...