What Make Them Different?
These two pictures were taken in the same plane, in the same window and with same camera. Can you see the different? Can you guest which country is? The fact of the matter is that the photo on the left was from Australia to take off; the photo on the right was land in China. 
As you can see, the sky of china and Australia are very different. You can see the blue sky and the white clouds in Australia which was very clear. In contrast, the sky of China was dusky and overcast, even the aerofoil was covered with dust. Why was there had such big different? In face, we can find that not only the Australia but many other countries have a clear blue sky. When I moved to the United States, I was completely attracted by the weather and the air. I can’t see the blue sky like that in china. I think maybe the foreign countries are vast in territory and small in population, so that the environmental pollution is not so serious. In China, with the increase of population, the air pollution is also becoming more and more serious. We need to consider more about the environment to prevent further deterioration of pollution. It’s possible that we can see the China sky as clear as the other country, as long as we have determination to solve.
All in all, these two photos can always remind us the importance of environment. Most of the Chinese think it’s good for senior to live in abroad. Because there have better environment and better air, maybe someday they will think live in China can be also very well.