The number of students in our school ________about 30,000 and ________them study hard.
| A．is; a large amount of | B．are; large amount of | C．are; a number of | D．is；a large number of |
People are concerned about the quality of the air they ______.
| A．hear | B．eat | C．drink | D．breathe |
She walked home by herself, ______ she knew that it was dangerous.
| A．if | B．so that | C．although | D．because |
—Let's go Dutch for this supper, OK?
—No，________this time, as a reward for all your help.
| A．it's up to you | B．it's my treat |
| C．let's talk about it | D．it doesn't matter |
At the United Nations Climate Change Conference, the UN Secretary General points out that，________， the climate situation will get worse and worse.
| A．if not dealing with properly |
| B．unless dealing with properly |
| C．if properly dealt with |
| D．unless properly dealt with |
—Who should be responsible for the accident?
—The boss, not the workers. They just carry the orders________.
| A．as told | B．as are told |
| C．as telling | D．as they told |