It is vital that every piece of equipment before the experiment.A. is checked B. will be

问题补充：

It is vital that every piece of equipment before the experiment.

A. is checked

B. will be checked

C. be checked

D. must be checked

答案：

A. is checked

B. will be checked

(答案→)C. be checked

D. must be checked

解析：本题考查虚拟语气。句型Itisvitalthat中，从句中谓语动词用should 加 动词原形，should通常可以省略。