7.Although the causes of cancer ____, we do not yet have any practical way to prevent it.
A.are being uncovered
B.have been uncovering
C.are uncovering
D.have uncovered
试卷相关题目
- 1— Just now Jenny gave ten dollars to a person in trouble.— She________others.
A.was always helping
B.is always helping
C.always helped
D.had always helped
开始考试点击查看答案 - 2I'll go to the teachers' office as soon as I finish what I _____.
A.wasdoing
B.amdoing
C.havedone
D.hadbeendoing
开始考试点击查看答案 - 3—Can you guess what’s the front page news today?—Of course, these days everybody _____ about the earthquake.
A.is talking
B.talked
C.has talked
D.had talked
开始考试点击查看答案 - 4The Internet, as well as newspapers and magazines, ________ a more and more importantpart in our daily life.
A.have played
B.are playing
C.is playing
D.has been played
开始考试点击查看答案 - 5—Do you think we should accept that offer?—Yes, we should, for we ________ such bad luck up till now, and time ________ out.
A.have had; is running
B.had; is running
C.have; has been run
D.have had; has been run
开始考试点击查看答案 - 6— ________ for the glass! —It’s OK. I’m wearing shoes.
A.Look out
B.Walk out
C.Go out
D.get out
开始考试点击查看答案 - 7—I hear you ________ in a pub. What's it like?—Well, it's very hard work and I'm always tired, but I don't mind.
A.are working
B.will work
C.were working
D.will be working
开始考试点击查看答案 - 8You forgot to go to the meeting? You _____important things. It’s so disappointing.
A.had always forgotten
B.are always forgetting
C.always forget
D.were always forgetting
开始考试点击查看答案 - 9Because the shop ______, all the clothes are sold at half price.
A.has closed down
B.closed down
C.is closing down
D.had closed down
开始考试点击查看答案 - 10--- Would you care for a cup of coffee? --- I ________ one. Thank you just the same.
A.had
B.have had
C.would have
D.will have
开始考试点击查看答案