7.So long as__________.

6.Firstly,________.

5.However,we have figured out many ways to________.

4.On the other hand,_________.

3.On the one hand,________.

2.So it is of graet importance for us to_________.

1.With the_______of________,________.(问题出现的背景)

12.In a word,_________.

问题解决型模板一

11.Last but least,________.

10.Second,________.