Question

英语单选一道。需解释。谢谢啦！

Answer 1

C
宾馆接待员必须确保顾客登记正确，这是很重要的

追答

不存在其他时态

Answer 2

同意3楼的，此处it is...固定用法，用启使语气，表强调，这里should可以省略

Answer 3

D
这类表“有必要的”形容词用于“it is + 此类形容词+ that从句”之结构中，that从句中需使用助动词should，但should常省略，而直接用动词原形。
常见的形容词有以下数个：
important、imperative、necessary、essential、urgent、desirable、advisable。
其句型结构：
it is important / imperative / necessary / essential / urgent / desirable / advisable + that + (should) + 动词原形
eg . It is imperative that Carlos should get married before his girlfriend changes her mind.
It is essential that nurses should learn to be patient .
It is advisable that you should take precautions before the typhoon arrives.
It is essential that abide by these rules.
It is advisable that he see a doctor immediately.

Answer 4

D，其实这个地方省略了一个should，it's important that、、、、、should do、、、

Answer 5

答案是C
该句为现在时态，所以否定A（现在完成时）和B(过去时）
hotel recetionist是单数，所以D也不合适 （单数主语要接makes sure)

如果考虑到It's important that从句省略should的情况，D也是正确的。

感觉这道题不严谨。