例句：
"You needn't be so rude about it." my wife answered as she looked at herself in the mirror.
“你说话没必要这么不客气”。我的妻子边回答边照镜子。
知识点：
need作情态动词时，后加动词原形；常用于否定句和疑问句中，needn't意为“不必” 。
You needn't be so polite to everyone here.
你不必对这里的每个人都这么客气。
need作实义动词时，有人称和数的变化，后加动词不定式、名词、代词或动名词。
I need to come in person.
我需要亲自来一趟。
My pants need a slide fastener.
我的裤子需要一条拉链：
This suit needs ironing.
这套西装应该熨烫了。（含被动含义）
