It has been announced that candidates remain in their seats until all the papers have been collected.
A. can
B. will
C. may
D. shall
网友回答
A. can
B. will
C. may
(答案→)D. shall
解析：shall用于陈述句的第二、第三人称时，表示说话人的意图、允诺、警告、命令、决心等，意思是“必须，应，可。”这句话的意思是：据宣布，考生在收卷前必须坐在自己的座位上。