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.
