Question

英语选择题的语法问题。

it was essential that the form __back before the deadline.A.must be B.be sent C.would be sent Dwas sent.答案是B请帮我分析下为什么其他几个不可以呢。

Answer 1

这个是被动语态,所以排除了A,
这个是一般过去式,所以排除了C
前面已经有一个was了,后面就只能接be的原形,所以排除D而选B.

Answer 2

这是一个句型，要记住。

be essential that sb./sth (should) do/be/be done

还有suggest/suggestion/advise/advice 也是这样的用法。

Answer 3

be essential (that) sb./sth (should) do/be/be done 是一个固定用法

另外,还有这样的用法的有
一坚持 insist
二命令 order command
三建议 suggest advise propose
四要求 ask demand require request

Answer 4

选B 虚拟 It was essential that sb./sth (should) do/be/be done
should可以省略

Answer 5

it is essential that....句型使用虚拟语气，实际上B选项省略了should