A-A+
It is essential that all these figures ______t
问题详情
It is essential that all these figures ______twice.
A．must be checked
B．be checked
C．is checked
D．will be checked请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：B
解析：这是一种虚拟语气。类似的还有“it is important；it is necessary”等。从句用 should do的形式，should可以省略。
