It was essential that the application forms back before thedeadline.
A. must be sent
B. would be sent
C. be sent
D. were sent
网友回答
A. must be sent
B. would be sent
(答案→)C. be sent
D. were sent
解析：这题考查虚拟语气的用法：在句型It‘s +adj+that从句中，如果adj是essential，necessary，natural等的话，that从句中用sb should do，should可以省略。句意是：申请书要在截至日期前送回来这是最基本的。选C。