If -------,we will continue our experiment after office hours

问题描述:

If -------,we will continue our experiment after office hours
A it be necessary B necessary
C it being necessary D be necessary
C为什么是错的呢>?这能不能构成独立主格结构?

B.这是条件状语从句中常用的省略手法,为的是避免重复累赘,补全应为If it is ……