英语情态动词解析The fire spread through the hotel very quickly but everyone get out.A.had to B.would C.could D.was able toIf he started at 9 0'clock,he be there by now.A.need B.shall C.ought to D.mustThe professor gave orders that the experim

英语情态动词解析The fire spread through the hotel very quickly but everyone get out.A.had to B.would C.could D.was able toIf he started at 9 0'clock,he be there by now.A.need B.shall C.ought to D.mustThe professor gave orders that the experim
英语情态动词解析
The fire spread through the hotel very quickly but everyone get out.
A.had to B.would C.could D.was able to
If he started at 9 0'clock,he be there by now.
A.need B.shall C.ought to D.must
The professor gave orders that the experiment before 5:30p.m.
A.be finished B.will finish
C.must be finished D.would be finished
______I go back before lunch?
No,I don't think you________.
A.Need...must B.Do...need to C.Must...have to D.May .ought to
D.D.A.B 我需要解析

英语情态动词解析The fire spread through the hotel very quickly but everyone get out.A.had to B.would C.could D.was able toIf he started at 9 0'clock,he be there by now.A.need B.shall C.ought to D.mustThe professor gave orders that the experim
1.The fire spread through the hotel very quickly but everyone_____ get out.
A.had to B.would C.could D.was able to
解析：句意——虽然宾馆里的火势蔓延得很迅速但每个人都能够逃出来.have to意思是是“必须做” ,would表示的意思是“将要“发生的事情,与句意不符合；can(could)和be able to都有”能够（做）“的意思.在表示过去的一般能力时,can和be able to两者没有很大差别,但如果要表示"一时的能力",即"在过去某时有某种能力,并顺利地完成某事",则要用 was / were able to,而不能用 could.
can ,be able to be able to 表示经过努力后,能够做到; be able to 有多种形式的变化.can 1).表示体力或脑力方面的能力; 2).表示允许、可能性.could 是can的过去式,表示过去有能力及过去存在的可能性 ; 用于疑问句表示委婉地提出问题.
2.If he started at 9 0'clock,he_____ be there by now.
A.need B.shall C.ought to D.must
解析：句意——如果他九点开始的话,他现在一定在这里了.need是”需要“的意思,与句意不符；shall表征询意见,用于第一、第三人称疑问句和表说话人的意愿,有“命令、允诺、警告、决心”等意思,用于第二、第三人称陈述句.不符合句意.这道题最有疑惑性的地方是C、D两项.ought to 是”应该“的意思,must 是”一定”的意思.但此句是条件语句,ought to表示主语的义务和责任的意味,此句没有这个意思.根据条件推测,所以只能选择must.
3.The professor gave orders that the experiment_____ before 5:30p.m.
A.be finished B.will finish
C.must be finished D.would be finished
解析：句意——教授要求实验要在下午五点半之前完成.从句中的主语为the experiment ,应该是“被完成”,应用被动语态,排除B.order/suggest/advise 等表示要求,建议,命令等词的后面如果有从句,从句要用虚拟语气,should + do,should 可以省略,故答案选A.
4.______I go back before lunch?
No,I don't think you________.
A.Need...must B.Do...need to C.Must...have to D.May .ought to
解析：此题的答案应该选C吧~
句子的意思应该是：我一定要在午餐前回来吗?——不,我觉得你不用必须回来.
第一题的拓展：can 与 be able to 均可表示某人做某事的能力,常可互换.例如：
I'm not able to [can't] explain this.我不能解释这个问题.
He was able to [could] speak French very well.他的法语讲得很不错.
但是两者还是有区别的：
(1) 从时态形式来看,can 只有现在式和过去式(could)两种,而 be able to 则可根据需要使用多种时态,还可以和一些情态动词连用,或用作动词不定式等非谓语形式.例如：
I haven't been able to sleep recently.最近我睡不着觉.
Our baby will be able to walk in a few weeks.我们的宝宝再过几个星期就能走路了.
You might be able to persuade him.你也许能够说服他.
I hope to be able to do the work.我希望能干得了这项工作.
I regret not being able to help her.我很遗憾未能帮助她.
(2) 用于现在时,can 泛指一般的能力,而 be able to 则主要指具体做某件事的能力.例如：
He can swim.他会游泳.
I am able to express my idea in a clear way.我能清楚地表达自己的想法.
(3) 在表示过去的一般能力时,两者没有很大差别.例如：
I could / was able to play the piano when I was young.我年轻时会弹钢琴.
但如果要表示"一时的能力",即"在过去某时有某种能力,并顺利地完成某事",则要用 was / were able to,而不能用 could.例如：
Though he was sick,he was able to swim across the river.虽然他病了,但他还是游过了河.
After five hours of climbing,we were able to reach the top of the mountain.经过5个小时的攀爬,我们终于登上了山顶.
could 表示可能或有能力做,was [were] able to 则表示能够做且确已做到.比较下面两句：
I was able to pass the examination.我通过了考试.（不仅有能力,而且实际上做到了.相当于I succeeded in passing the examination.）
I could pass the examination.我当时有能力通过考试.（有能力,但实际上不一定做得到）