引用：
One of the greatest early writers said ...
"Knowledge is power", such is the remark of ...
"......". That is how sb comment ( criticize/ praise...).
"......". How often we hear such words like there.
讲故事
(先说故事主体)，this story is not rare.
..., such dilemma we often meet in daily life.
..., the story still has a realistic significance.
提出原因：
There are many reasons for ...
Why .... , for one thing,...
The answer to this problem involves many factors.
Any discussion about this problem would inevitably involves ...
The first reason can be obviously seen.
Most people would agree that...
Some people may neglect that in fact ...
Others suggest that...
Part of the explanation is ...
进行对比：
The advantages for A for outweigh the disadvantages of...
Although A enjoys a distinct advantage ...
Indeed , A carries much weight than B when sth is concerned.
A maybe ... , but it suffers from the disadvantage that...
承上启下：
To understand the truth of ..., it is also important to see...
A study of ... will make this point clear
让步：
Certainly, B has its own advantages, such as...
I do not deny that A has its own merits.