我常坐的火车取消了。这就是我这么晚的原因。

My usual train was cancelled. ___That's why I'm so late.

她骗了他，那正是让他真正心烦的事。

She tricked him, and ___that's what really upset him.

我决定不再踢足球了。这就是我想卖掉它们的原因。

I decided not to play football any more. ___That is why I want to sell them.