________ there is no restriction on foreign entries at the film festival ，those that win are in minority.
A. unless B. When C Where D while
It was with great joy _______ he worked out the problem that he had long been puzzled about.
| A．which | B．that | C．because | D．since |
The manager is always very _______ for appointments, which earns him a good reputation.
| A．punctual | B．numb | C．allergic | D．content |
_______ this sentence a second time, the meaning will become clear to you.
| A．If reading | B．When you read | C．Reading | D．Read |
Global warming is a big _______ for all and it’s important to raise awareness about climate change.
| A．reward | B．concern | C．evolution | D．boom |
— You _______ for me this morning. I came over here with Michael in his car.
— Well, why didn’t you let me know earlier?
| A．should have waited | B．would have waited |
| C．couldn’t have waited | D．needn’t have waited |