问题
选择题
He is very sick. I insist that a doctor __________ immediately.
A．has been sent for
B．sends for
C．will be sent for
D．be sent for
答案
答案：D
这题考查虚拟语气，insist表示“坚持要求”，宾语从句用should+do，should可以省略，a doctor和send for是被动关系，选D。