It was the order that all the soldiers to the front.A. should send B. must be sentC. be s

问题补充：

It was the order that all the soldiers to the front.

A. should send

B. must be sent

C. be sent

D. must go

答案：

A. should send

B. must be sent

(答案→)C. be sent

D. must go

解析：考查虚拟语气。本题实际上是一个同位语从句，对前面的名词order的内容进行解释说明。在同位语从句中，如果名词是order的时候，后面的同位语从句使用”should+动词原形”；should可以省略。句意：所有的士兵都要从前线撤退，这就是命令。故C正确。