It has been announces that all takers remain in their seats until all the exam papers hav

问题补充：

It has been announces that all takers remain in their seats until all the exam papers have been collected.

A. can

B. may

C. shall

D. will

答案：

A. can

B. may

(答案→)C. shall

D. will

解析：shall用于二三人称表示命令、警告、允诺，尤其用于正式的法律条文中。

【标签】情态动词