The sign "No Smoking" in the subway means passengers ____________ smoke.
can
should
mustn't
needn't
Li Mei is the student _________ handwriting is the best in our class.
Neither my father nor my mother ________ rock music. They think that it’s too ______.
Great changes _________ in Tongren in the past five years.
—Can you tell me _________? —I lost my MP3 player.
If it ________ this Saturday, we will ________ for a picnic.