A possible version

As the global climate becomes warmer and warmer, our earth is facing great threats. As a high school student, I believe everyone has the obligation to do something to save our home. Earth Hour is an activity that we can take part in. Let's turn off the lights and computers. It lasts an hour at a certain time. This is an easy job for us, but if we all do it together, it will save a lot of energy. More people will realize the problems facing our planet and start to take action. Let's form the good habit of saving energy in our daily life and strive to make more contributions to our environment.

Test and analysis: The topic requires writing an English proposal, calling on everyone to join the environmental protection activities of "Earth Hour, a big step for mankind". The main points of the composition have been listed, but we should not only translate each point, but also pay attention to the contextual cohesion of the composition. Writing in the first person is more convincing. Use more advanced vocabulary and important sentence patterns, and pay attention to the neatness of the paper.

The highlights show that the model essay uses phrases to face, participate, close, take action and make contributions. , make the composition more substantial. The model essay uses many important sentence patterns: using composite structure and global warming; ; It is everyone's duty ...; ; An activity we can do and the problems facing our earth. Finally, the model essay uses the imperative sentence Let's ... to mobilize everyone to participate and achieve the purpose of writing.