must usually certainly can/may only absolutely essential can should necessary to need to should not (shouldn t) will won t unnecessary to need not (needn t) it is optional may might have to sometimes it is possible yet always cannot (can t) not required to strictly prohibited never could often ought to don t have to but however an exception is on the other hand must not (mustn t)
问题:The Macintosh computer network can only be used A I N by second and third year students.
声带内容:“The Macintosh computer network is reserved for second and third year students only ...” 考生听到这里为止会认为答案是对的,但句子的后部是:“... unless you are a first year student of the Graphic Design course.”因此作答时要小心,不要分神。