为何不选should be?

问题描述:

为何不选should be?
oh,its 1:30 pm.you ____hungry.lets go to the nearest restaurant.
A should be
B shall be
Cwill be
D must be

shall,是用于第一人称的,即I和we,在建议第二人称的人(you)时,should.而且should,也是shall的过去式
例:你应该去看看医生—You should go to see a doctor.
我们应该坐下—we should sit down.
通常用should比用shall多,而且should的语气比较委婉.
must与 be 连用,表示猜测、推测,在使用中要注意这个情态动词短语的两个方面.
1、反意疑问句:主语 must be..., be not 主语(代词)?类似的用法还有may be.
eg. They must be late, aren't they?
It may be in your pocket, isn't it?
2、否定句:must be 与may be 的否定形式为 can't be.
eg. They must be late. --(否定)They can't be late
It may be in your pocker. --(否定)It can't be in your pocket.
must 与行为动词连用,在变为反意疑问句的时候,就可以直接使用mustn't .
eg. He must finish it at once, mustn't he?