Doctor：You needn't go on a diet；but you must eat sensibly1 and youmustn't overeat．
大夫：你不必节食，但要饮食有度，不可以吃得过饱。
Zoo notice：Visitors must not feed the animals．
动物园通告：参观者不能给动物投喂食物。
Railway notice：Passengers must not walk on the line．
铁路通告：旅客不能在铁路线上行走。
You mustn't drive fast．There is a speed limit here．
你不可以开快车。这地方有速度限制。
You needn't drive fast．We've plenty of time．
你不必开得快。大家时间足够。
You needn't strike a match．I can see well enough．
你不需要划亮火柴。我可以看清。
You mustn't strike a match．This room is full of gas．
你不可以划火柴。这屋里满是煤气。
School notice：The lifts must not be used during Fire Drill2．
学校通告：在消防演习期间禁止用电梯。
You mustn't wear that dress again．You look terrible in yellow．
你不要再穿那套裙装了。你穿黄色难看极了。
Teacher：You needn't read the whole book but you must read the first four- chapters．
老师：你们不必把整本书全读完，但需要读完前四章。
You must cut down that dead tree or it will fall on your house．
你需要把那棵死树砍了，不然它会倒在你的屋顶上。
Doctor：You mustn't take more than two of these pills at once．Three might be fatal3．
大夫：这类药你每次服用时不能超越两片。服三片就可能有生命危险。
Doctor（to patient's wife）：If the pain has gone he needn't take any more of these．
大夫（对病人的老婆）：假如疼痛已经消失了，他就不必再服这类药片了。
