The reason why he failed is ________he was too careless.

Go and get your coat. It’ s ________you left it.

The problem is _________to take the place of Ted.

What I want to know is ______ he likes the gift given by us.

That is ______ Lu Xun once lived.

That is  __ ___ we were late last time.   

—I fell sick!

—I think it is _______ you are doing too much.