4971.motor(名)马达、原动力
He startod the motor.
他启动了发动机。

4972.mountainous(形)多山的
Taiwan is a mountainous regian．
台湾是个多山的地方。

4973.movable(形)可移动的
Christmas is fixed,but Easter is a movable feast.
圣诞节的日期是固定的，但复活节的日期却因年而异。

4974.mug(名)马克杯
He drank a mug of coffee．
他喝了一大杯咖啡。

4975.murmur(动)喃喃自语、私语；发出轻柔持续的声音
The wind murmured in the trees.
风在林中低鸣。

4976.muscle(名)肌肉；实力
The movement flexed black political muscles.
这场运动显示了黑人的政治实力。

4977.muscular(形)肌肉的
He wished he was more muscular and didn't have such a flat chest.
他但愿自己更健壮些，胸部不会这么扁平。

4978.muse(动)沉思(名)缪斯女神；诗兴
(动):I sat quietly, musing on the events of the day.
我静静地坐着，沉思一天中所发生的事。
(名):He felt that his muse had deserted him.
他觉得他已失去了创作灵感。

4979.museum(名)博物馆
His works were hung in many museums.
他的作品被许多博物馆收藏。

4980.musical(形)音乐的
She's very musical.
她极具音乐天赋。

4981.musician(名)音乐家
The conductor of the orchestra is a musician.
管弦乐队的指挥是个音乐家。

4982.mute(形)哑的、沉默的(名)哑巴；静音
(形): The child has been mute since birth.
那孩子生下来就是哑巴。
(名):He turned on the "mute" key of the TV in order to hear me clearly.
他把电视开到无声以便听到我的话。

4983.mutter(动)喃喃自语
We heard the man muttering something as he walked away.
我们听到那人一边走开一边咕哝着什么。

4984.mutton(名)羊肉
The mutton was seasoned with garlic.
羊肉加了大蒜调味。

4985.mutual(形)相互的
We have a mutual agreement to help each other out when necessary．
我们彼此有协议，必要时要互相帮助渡过难关。

4986.myth(名)神话
when you are dealing myths,it is hard to be either proper，or scientific．
当你面临神话般的吸引力时，你就很难做到合理或是与科学共存。

4987.nag(动)唠叨、不断地挑剔
She had been nagging him to paint the fence.
她一直唠叨，要他把围栏油漆一下。

4988.naive(形)天真的；质朴的、朴素的
I can't believe you were so naive as to trust him!
真是难以相信你会轻易信任他！

4989.naked(形)赤裸的
They often wandered around the house naked.
他们经常赤身裸体地在房子周围谩步。

4990.napkin(名)餐巾
She folded the napkin into tha shape of a water lily.
她把餐巾折成百合的形状。

4991.naval(形)海军的
He is a retired naval officer.
他是一位退役的海军军官。

4992.Navy(名)海军
N常大写
The Navy is considering buying six new warships.
海军正在考虑购买六艘新战舰。

4993.nearsighted(形)近视的
Nearsighted people usually wear glasses．
患近视的人一般都戴眼镜。

4994.necessarily(副)必要地
The number of places available is necessarily limited.
可用场所的数量不可避免地有限。

4995.necessary(形)必要的
同义词essential
It doesn't seem necessary for us to meet.
我们似乎没必要见面。

4996.necessitate(动)使成为必要
The increase in population necessitates a greater food supply.
人口的增加需要更多的食物供应。

4997.necessity(名)必要性；必需
Emphasis is laid on the necessity that all the objectives to be attained should be taken into account before starting a new plan．
要强调的是，在开始一项新的计划之前，将要达到的所有目标都纳入考量是必要的。

4998.negative(形)负面的、否定的
Most substances taken in excess will produce negative effects such as poisoning or intanse perceptual distortions.
大部分物质，一旦使用过量，就会产生负面影响，比如中毒或严重知觉扭曲。

4999.neglect(名)疏忽、忽视
同义词overlook
The garden was in a state of total neglect.
那花园完全无人整理。

5000.negotiate(动)谈判
The government will not negotiate with terrorists．
政府不会和恐怖分子谈判。

5001.negotiation(名)谈判
惯用复数
The rent is a matter for negotiation between the landlord and the tenant.
租金可以由房东和住户协商确定。

5002.nephew(名)侄儿；外甥
The aunt went shopping with her two nephews.
阿姨带着她的两个侄子买东西去了。

5003.neutral(形)中立的
He remained neutral during the debate.
他在辩论中保持中立。

5004.navertheless(副)然而、仍然、不过
There is little chance that we will succeed in changing the law. Nevertheless,it is important that we try.
我们几乎没有可能改变法律。不过，重要的是我们要努力争取。