This question is so hard that very ______ students can answer it.

The story is about Lei Feng.It’s very ______.

I have finished my homework already, mum.— When ________ you ________ it?

Have you got;E-mail address?—Oh yes, mine is wjb80@yahoo. com,

You’ve chatted for nearly two hours. — Yeah. We’re talking about the things ______ happened yesterday.