定语从句

The Yangtze River is the longest river in China, which is prevented from being polluted.

强调句

It is we who are the owners of the earth.

简单句

Protecting the environment.

It‘s our duty to protect our environment.

It is very important to take care of our environment.

We should not throw litter onto the ground.

We should not spit in a public place/ cut down.

Clear waters and green.

We should stop factories from producing harmful gases.

Save the earth, Our Only Home.

As we know , water is very important to man.

并列句

Environmental conservation （环境保护） and pollution control （污染控制） are essential.

复合句

If we continue to ignore the importance of environmental protection, the consequences will be dire.

这些句子涵盖了定语从句、强调句、简单句、并列句和复合句等多种语法结构，并且都与环保主题相关。希望这些例子对你有所帮助。