This is a very difficult operation.It is essential that you ________ for emergencyA.are to be prepared B.would preparedC.be prepared D.must be prepared
问题描述：
This is a very difficult operation.It is essential that you ________ for emergency
A.are to be prepared B.would prepared
C.be prepared D.must be prepared
答
选C啊
答
选C，虚拟语气，省略should
答
this is a very difficult operation. It is essential that you be prepared for emergency.
choose C
这是一个很难的操作。你必须对紧急情况有所准备。
答
A
答
答案选C 这里是虚拟语气 从句应该用should+原形,should可以省略 it is +necessary等形容词后,that主语从句中虚拟形式使用,这类形容词包括necessary,important,essential,imperative,urgent,preferable,vital,advisab...