（一） a1 vs a2 = contrast “对照”即是一个事物的两方面做比较，如看电视的利弊，出国留学等等，a1好，a2坏；或是a1坏，a2好 （二）a vs b = compare 对比 即是两个事物做比较，如锻炼是跑步好还是做操好等，a b同好或是同不好
段二 回到a （a1）
段三 回到b （a2）
段四 结尾 选择类 a or b
表态类（用死不表态法） a1 vs a2
1．when it comes to the issue (phenomenon) of ……( tuition fee;tv effects), different people have radically different opinions. some people hold onto the idea that ……. other people ,however, deem that…….
2. as regards the issue of……,there is a popular discussion. some people … other people ,however,……
开头：…… because of the following factors.
开头 by comparison,
a or b
in the similar way,
a1 vs a2
quite on the contrary,
just as any coin has two sides, it’s no exception with the issue of …. actually the issue is just like a double-edged sword,and we should try every means to avoid its harmfulness while at the same time, making the most of its advantages.
as discussed above, each side has its advantages and disadvantages. if i’m allowed to make a decision, i prefer a to b ( b to a) , for the following reasons. on one hand,….. on the other hand,……