It+be+形容词或过去分词+主语从句 当形容词为important时,要用虚拟语气.It is important that the committee be informed about the project at once.我不是很懂虚拟语气.

It is important that the committee (should) be informed about the project at once.
主句中有IMPORTANT(重要），所以后面的从句动词要用虚拟语气，这里虚拟语气的构成是动词原形或者SHOULD+动词原形

It is important that the committee be informed about the project at once
这是一句虚拟语气
省略了should
完整的应该是It is important that the committeeshould be informed about the project at once