It was ______ the old worker came that we______ the experiment.
| A．until；didn’t begin | B．not until; began |
| C．until; began | D．not until; didn’t begin |
.
If I can help ____, I don’t like working late into the night.
| A．so | B．that | C．it | D．them |
.
---Why not open the windows to let _____cool air in?
---I’d rather you didn’t. ________air in out town is terribly polluted.
| A．a; The | B．/; The | C．/ ;/ | D．the; / |
.
.----Are my clothes too casual?
----No. You can go ____you are.
| A．as | B．what | C．that | D．where |
.
How ___I help them to understand when they won’t listen to me?
| A．can | B．would | C．may | D．must |
.
.In summer, food will go bad if________in room temperature.
| A．leaving | B．left | C．being left | D．having left |