问题补充:
—Look! A book is on the floor. Whose is it?
—It be Rick’s. It has his name on it.
A. mustn’t
B. can’t
C. must
D. need
答案:
A. mustn’t
B. can’t
(答案→)C. must
D. need
解析:mustn’t一定不,禁止;can’t不可能;must 必须,一定;need需要。句意:看,地板上有本书。是谁的?——一定是瑞克的。上面有他的名字。结合语境可知选C。