1、对立法

一般先引出其他人的不同观点，然后提出自己的观点或自己偏向的观点。对立法适用于有争议的主题，例如：

1.Some people say / believe / hold the view /claim / suggest that______. Others criticize / point out / maintain / argue that______.

2.Nowadays it is universally / generally  admitted / acknowledged / accepted /  held that______. But I wonder/ doubt whether______.

2、概括法

1.Recently, the rise in the problem /  phenomenon of has aroused public / popular /wide  concern.

2.Recently the issue of______has been brought into focus / brought to public attention.

3、引用法

先引出名人名言或有代表性的观点，再引出文章要展开论述的观点，其常用句型有：

1.There is an old saying that / People often say / It is often quoted  that______. How often we hear such statements / words as these.

2.______once said that______. We can learn from words that______.

4、比较法

通过比较与文章主题相关的观点来引出自己的观点，其常用句型有：

1.For years, ______have been viewed as______.But people are taking a fresh look now. With the growing______, people______.

2.People used to think that______. (In the past，______.) But now people share a new idea of______.

5、问题法

通过提出一个或一连串的问题，可以激发读者的兴趣，从而引出主题。例如：

1.Should/ What______? Options of______vary greatly；some______,while others______. But in my opinion, ______.

6、调查法

为了得到读者的认可，文章的开始可以引出调查数据等，借以提出主题。例如：

1.Although the popular belief  is that______, a current (new/recent) study(survey / poll / investigation) indicates (shows / demonstrates) that______.

2.It was reported by scientific studies that / Evidence had shown that______.

来源：网络