The light in his office is still on. Do you know _______—To prepare for the material(材料) the meeting will need tomorrow, I think.

The bell ________ the end of the period rang,________ our heated discussion. [ ]

I like talking on the Internet with my friends.—- ______.

She had a bad cold, but luckily began to _______ soon.

下列各句中，没有语病的句是