1:non-smoking section
The boss wanted to make reservation for a room in a non-smoking section.
smoking section
2:nose dive
After breaking up with Mary, Tom's study took a nose dive.
3:not always be the case
Most people think that lions only come from Africa. And you would be forgiven for thinking this, because in fact most lions do come from Africa. But this hasn't always been the case.
4:not for circulation
Sorry, all of the books in this library are not for circulation.
5:not have a clue about
Do not ask the old man which key to press-he doesn't have a clue about computers.
6:not mean any offense on
You know, I don't mean any offense on these disabled people.
7:not only...but also
There are an increasing number of opportunities for young people to work for a period in Antarctica-not only as research assistants in projects like mine, but also in a wide range of junior administrative and technical positions including vacancies for map-makers.
8:not to mention
It's far too early for you to go out and play basketball, not to mention the fact that it's snowing.
needless to say
9:not...but rather
Actually,Thomas Edison didn't do the work himself but rather asked a young Scotsman in his employ to design a projection system
10:note down
A:Should I be drafting the chapter two of my dissertation?
B: No, but I think you should note down its main sections.

雅思詞組1:無煙區，禁煙區

老板想在無煙區預訂一個房間。

表“吸煙區”。

雅思詞組2:俯沖;暴跌，急劇下降

跟瑪麗分手后，湯姆的學習成績一落千丈。

雅思詞組3:情況不會一直是這樣的

大多數人都認為獅子只生活在非洲，這樣想情有可原，因為實際上大多數獅子的確都來自非洲，但并非一直如此。

雅思詞組4:不外借

對不起，這個圖書館的所有書籍概不外借。

雅思詞組5:不了解，不知情

不要問這個老人應該按哪一個鍵，他對計算機一竅不通。

雅思詞組6:不是有意冒犯

你知道，我并非有意冒犯這些殘疾人。

雅思詞組7:不但…而且，不僅…還

年輕人有越來越多的機會在南極洲工作一段時間—不僅在采礦類項目中擔任研究助理，還可任職于各種中級管理和技術崗位，如地圖繪制員。

雅思詞組8:更不用說

你現在出去打籃球太早了，更何況還在下雪。

雅思詞組9:不是…而是

實際上托馬斯·愛迪生并沒有親自做這件事，而是雇用一個蘇格蘭人設計了一個放映系統。

雅思詞組10:記錄，記下

A:我應該開始為論文的第二章打草稿了嗎?

B:不用，但是我認為你應該記下第二章的主要部分。