The experiment _____ last week.A.ought to be done B.ought to do C.ought to have been done D.ought to have done为什么?我选A不对吗?为什么用现代完成时?过去时不行吗?既然是应该过去做为什么不用过去完成时?

THE HOCKEY EXPERIMENT怎么样 theoldprofessorgaveordersthat,the.experiment[]before6 the news feed experiment 他反复地实验,直到成功.He did the experiment ____ ____ ____ _____ he succeeded. The experiment the students of science devoted themselves to _____ at last.A.succeedB.succeedingC.have succeededD.succeeded讲讲 To our delight,the result of the experiment is entirely _____ with what we expected.为什么不能填satisfied 死亡实验 THE EXPERIMENT怎么样 英语翻译Much _____(使研究人员感到惊讶),the outcome of the experiment was far better thanthey had expected.答:surprised as the researcher felt这样回答行不行? The experiment _____ the discovery of a cure of cancer.a.resulted in b.resulted from c.led up d.set up给下理由, I have the same opinion as yours _____ we should carry out the experiment at once.A.that B.which C.whether D.where 蒸汽实验 THE STEAM EXPERIMENT怎么样 恐怖实验 THE TERROR EXPERIMENT怎么样 费城实验 再生 THE PHILADELPHIA EXPERIMENT怎么样 This is 什么 want for the experiment F___these instructions to do the experiment. It was not until mid-night _____ he went back home after the experiment.A.when B./ C.that D.before [单选题]1.It was the third time _____ he had done this experiment.A.since B.before C.which D.that the teacher is _______with the experiment done by him [satisfy ]