I wrote to my parents once a week,____ I was too busy with my teaching work.
| A．it | B．unless | C．when | D．as |
_______ you get on well with a number of people, you are usually friends with only a few .
| A．Since | B． Where | C． Before | D．While |
---- It’s the office! So you _____ know eating is not allowed here.
---- Oh, sorry.
| A．must | B．will | C． may | D． need |
You should write a _____________ composition every other week.
| A．three- thousand- word | B．three- thousands – word |
| C．three – thousand – words | D．three – thousands- words |
Although _______ my opinion, the old professor didn’t come up with his own.
| A．against | B．on | C． for | D．in |
Anyone , once _______ positive for H7N9 flu virus , will receive medical treatment from our government.
| A．to be tested | B．being tested | C．tested | D．to test |