It is suggested that some skills teachers to teach the children in these mountainous are

问题补充：

It is suggested that some skills teachers to teach the children in these mountainous areas .

A. must be sent

B. be sent

C. should send

D. should send for

答案：

A. must be sent

(答案→)B. be sent

C. should send

D. should send for

解析：suggest构成从句，从句中用虚拟，should+do,should可省略。