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.

雅思词组1:无烟区，禁烟区

老板想在无烟区预订一个房间。

表“吸烟区”。

雅思词组2:俯冲;暴跌，急剧下降

跟玛丽分手后，汤姆的学习成绩一落千丈。

雅思词组3:情况不会一直是这样的

大多数人都认为狮子只生活在非洲，这样想情有可原，因为实际上大多数狮子的确都来自非洲，但并非一直如此。

雅思词组4:不外借

对不起，这个图书馆的所有书籍概不外借。

雅思词组5:不了解，不知情

不要问这个老人应该按哪一个键，他对计算机一窍不通。

雅思词组6:不是有意冒犯

你知道，我并非有意冒犯这些残疾人。

雅思词组7:不但…而且，不仅…还

年轻人有越来越多的机会在南极洲工作一段时间—不仅在采矿类项目中担任研究助理，还可任职于各种中级管理和技术岗位，如地图绘制员。

雅思词组8:更不用说

你现在出去打篮球太早了，更何况还在下雪。

雅思词组9:不是…而是

实际上托马斯·爱迪生并没有亲自做这件事，而是雇用一个苏格兰人设计了一个放映系统。

雅思词组10:记录，记下

A:我应该开始为论文的第二章打草稿了吗?

B:不用，但是我认为你应该记下第二章的主要部分。