803.What does the sign over there read?
No person _______ smoke or carry a lighted cigarette,cigar or pipe in this area.
A.will
B.may
C.shall
D.must
804.Guess what?I have got an A for my term paper.
Great!You ____ read widely and put a lot of work into it.
A.must
B.should
C.must have
D.should have
803.答案是C;shall用于第二，三人称，表示命令，需要，警告，威胁等，此处表示警告。
804.答案是C;根据have got an A推测过去肯定发生的事情。
