1.It isn't cold enough for there____ a frost tonight,so i can leave his car out quite safely.A.would be B.being C.was D.to be2.The number of registered participants in this year's marathon was half________.A.of last year's B.those of last year's C.of

1.It isn't cold enough for there____ a frost tonight,so i can leave his car out quite safely.A.would be B.being C.was D.to be2.The number of registered participants in this year's marathon was half________.A.of last year's B.those of last year's C.of
1.It isn't cold enough for there____ a frost tonight,so i can leave his car out quite safely.
A.would be B.being C.was D.to be
2.The number of registered participants in this year's marathon was half________.
A.of last year's B.those of last year's
C.of those of last year's D.that of last year's
3.I would have gone to visit him in the hospital had it been at all possible,but I ____fully occupied the whole of last week.
A.were B.had been C.have been D.was
(此题为何不能选B?)
第三题是选B，为什么不能选D？

1.It isn't cold enough for there____ a frost tonight,so i can leave his car out quite safely.A.would be B.being C.was D.to be2.The number of registered participants in this year's marathon was half________.A.of last year's B.those of last year's C.of
1. It isn't cold enough for there____ a frost tonight, so i can leave his car out quite safely.
A. would be B. being C.was D.to be
答案详D. 这个是there be句型的非谓语形式,如果放在“It be + adj. for...”的结构中,使用there to be.你查there to be这个百度百科,就有详细解释,我就不多写了.但在这里我告诉你个简单方法,把there be当成是 sb do代入,因为是for sb to do sth,所以这里就是there to be.其他结构也是同样代入.你到百科里面的例句上试试.
2. The number of registered participants in this year's marathon was half________.
A. of last year's B. those of last year's
C. of those of last year's D.that of last year's
答案详D. 这里的that指代的是the number.两个数量之间进行的比较.
3. I would have gone to visit him in the hospital had it been at all possible, but I ____fully occupied the whole of last week.
A. were B. had been C. have been D. was
(此题为何不能选B? )
问题补充：第三题是选B,为什么不能选D?谢谢
答案就是D,这个是97年的全国硕士研究生入学考试的试题.这个句子前面是个对过去情况进行虚拟的虚拟语气,但它是省略if,had提前的语序.写完整应该是这样的： I would have gone to visit him in the hospital, if it had been at all possible.如果当时有可能的话, 我应该去医院看望他的.但是我上周很忙.but后是对上周情况的陈述,用过去式就可以了.
感谢对我的信任,希望能明白.不明白再留言给我,有空的话我会回答你的问题的.

我认为是DDD
1.相当于句型“It`s cold for sb to do sth”
2.number 是单数用“that”指代
3. B代表过去的过去发生的事，这里仅代表过去发生的事。

B
D that就是个代词，代指前面的内容The number
B

1.Bfor 为介词"因为"后用ing 形式.
2.Dthat 代number
3.B虚拟语气时态往后推一.过去时要变为过去完成时