人教版选择性必修二英语课文原文全文如下：

Unit 2 Environment Protection。

Text 1：Air pollution is a serious problem in many cities.

Text 2：Many people think that we should protect the environment.

Text 3：Pollution is one of the biggest problems that we have to face today.

以上是部分原文内容，如需全文请查询人教版高中英语教材。