—Who is the girl standing over there?
— Well, if you _____ know, her name is Mabel.
A. may B. can C. must D. shall
—Who is the girl standing over there?
— Well, if you _____ know, her name is Mabel.
A. may B. can C. must D. shall
D
shall 用于陈述句第二、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、应该、可以”。句意:据宣布,考生在收卷前必须坐在自己的座位上。