1.拓展于形式

for example---举例

while---对比

because of that---因果

given that condition---因果

This is natural, and unnecessary to be changed 段落小结

2. 拓展于义

拓展段落的连接方法

（1）关联法

be directily linked to

be closely connected with

be largely associated with

（2）用“因为”表达原因

（3）用动词词组表达结果

lead to

give rise to

contribute to

(4) 用从句来引入例子

A clear case in point is that...

A typical example can be found in...

(5) 时间对比的表达

（6）特性对比的表达

On the contrary

By the same token,... 

(7) 段落小结

It is little wonder that...

Therefore, it is no exaggeration to say that...