1.段內並列
分析某事物時，用此句型說明其主要原因或者多方面原因
例如：Why…? For one thing …For another …There are many reasons for this problem. First /For one thing …Second / For another …Third/ Still another …
2.段內延伸
例如：In involves some serious consequence for …
3.段內對比
(1)肯定其中一個
The benefits gained from B are much greater than that of A.
(2)二者有共同點
A and B have several things in common are similar in that…
