问题
选择题
—The old man is ill. He ________ to the hospital at once.
--Don’t worry. A doctor _________to come already.
A．must be sent , has asked
B．must send, have asked
C．must be sent, has been asked
D．must send, have been asked
答案
答案：C
题目分析：句意：---这个老人生病了他必须马上被送到医院，----不要担心，医生已经被叫来了。 Must be done 表示含情态动词的被动语态，完成时的被动语态have been done 结构，根据题意可知选C