【示例一】
①There are many reasons responsible for this phenomenon/case/instance and the following are the typical ones. ②The first reason is that ________（理由一）。 ③The second reason is that ________（理由二）。 ④The third reason is that/A case in point is that/The typical example is that ________（理由三）。
【示例二】
①There are many reasons to explain/explaining the effect/phenomenon/case/instance. ②The most contributing one is/the main reason is no other than ________（理由一）。 ③What is more, ________（理由二）。 ④ ________（理由三）also play a role in this case.
①There are many reasons responsible for this phenomenon/case/instance and the following are the typical ones. ②The first reason is that ________（理由一）。 ③The second reason is that ________（理由二）。 ④The third reason is that/A case in point is that/The typical example is that ________（理由三）。
【示例二】
①There are many reasons to explain/explaining the effect/phenomenon/case/instance. ②The most contributing one is/the main reason is no other than ________（理由一）。 ③What is more, ________（理由二）。 ④ ________（理由三）also play a role in this case.
