—What does PM 2.5 mean?
—It's a professional ________ indicating the condition of air pollution.
| A．term | B．item | C．number | D．mark |
The new policy allows a couple to have a second birth____either is an only child.
| A．if only | B．on condition that |
| C．unless | D．until |
It’s crazy of you to spend more time playing computer games than you _______ studying.
| A．are | B．have |
| C．do | D．will |
--Do you think you can finish the project by five o’clock this afternoon?
---_______. I’ll be busy with my term paper all day.
| A．Not a little |
| B．Not a chance |
| C．Not a bit |
| D．Not to mention it |
This hotel is the highest building in the city, from _______ top you can enjoy a good view of our city.
| A．which | B．its |
| C．that | D．whose |
Knowing what colors look good _______ your skin is of great importance when you buy clothes.
| A．beyond | B．within |
| C．against | D．over |