有读者问： 有两道选择题：
(1)Tell him that he_________come here immediately.
A. shall B. will C. need D. would
(2)_____ he open the door?
A. Shall B. Will C. Can D. Would
答案都是A，我不知为什么。
上述句（1）之所以应选A，是因为表命令的shall亦可用于第三人称，再如：
(3)He shall do it, whether he wants to or not.
上述句（2）之所以应选A，是因为表示征求对方意见的shall也可用于第三人称，再如：
(4)What shall he do next?
(5)Shall the messenger wait?
