知识要点：
1. 并列句：由两个或两个以上的简单句并列连接起来的句子叫并列句。
2. 并列句的基本句型：简单句 + 并列连词 + 简单句
3. 并列句的类型：
1) 并列关系（联合关系）。连接词：and, not only…but (also), neither…nor等
例句：I help him and he helps me.
我帮助他，他也帮助我。
Not only did we write to her but also we tele graphed her.
我们不仅给她写信而且还给她发了电报。
Neither I would consult him nor he would ask me for advice.
我不想与他商量，他也不会征求我的意见。
2) 转折关系。连接词：but, yet, still, while, however, when等
例句：He failed many times, but he didn’tdespair.
他失败多次但并没有气馁。
She has difficulty in learning English, however, she works hard and is making rapid progress.
她学习英语有困难，然后她学习努力，进步很快。
3) 选择关系。连接词：or, otherwise or else, either…or
例句：We must hurry, or we’l miss the train.
我们必须快点，否则会赶不上火车。
Either you come to my place or I go to yours.
或者你到我这儿来，或者我到你那去。
4) 因果关系。连接词：for, so, thus, therefore, and so
例句：We had better stay at home, for it was raining.
我们最好呆在家里，因为天正在下雨。
He didn’t work hard, therefore he failed in the examination.
他学习不努力，因此这次考试不及格。
有时也可不用连词，而用逗号，分号或冒号。如：
Hurry up, it’s getting dark.
快点，天要黑了。
Let’s start early, we have a long way to go.
我们要早动身，因为路很远。