All the students in our class buried themselves ________studies，________
the coming exam.
| A．in；preparing |
| B．in；preparing for |
| C．for；prepared |
| D．for；prepared for |
scientists have learned a lot about the universe, there is much we still don't know.
| A． | Once | B． | Since | C． | Though | D． | Unless |
If you come to visit China, you willa culture of amazing depth and variety.
| A． | develop | B． | create |
| C． | substitute | D． | experience |
— Can you come to a party on Saturday, Peter?
— Oh, ______I'm already going out, I'm afraid.
| A．what a pity! | B．don't ask! |
| C．how come? | D．so what? |
―I’ve got something weighing on my mind. Could you give me some advice?
―______. Tell me all about it and I’ll do what I can.
| A．Don’t mention it | B．No way |
| C．No problem | D．Forget it |
Being constantly exposed to advertisements is annoying, but it ______ be pleasant sometimes.
| A．shall | B．need | C．can | D．must |