If you want to do the experiment again, you had better be more careful ________ you made a mistake.
| A．when | B．why | C．where | D．that |
一 When did the computer crash?
一 This morning, while Ithe reading materials downloaded from some websites.
| A．have sorted | B．was sorting | C．am sorting | D．had sorted |
The air quality in the city, ________is shown in the report, has improved over the past two months.
| A．that | B．it | C．as | D．what |
一 Have you figured out how much the trip will cost?
—$4,000, orlike that.
| A．anything | B．everything | C．something | D．nothing |
—What are you going to do this weekend?
. If time permits, I may go to Shanghai with my friends.
| A．Don’t mention it | B．It doesn’t matter | C．Forget it | D．It depends |
We promiseattends the party a chance to have a photo taken with the movie star.
| A．who | B．whom | C．whoever | D．whomever |