A composition, the title: … has changed …, for example, it is getting dark, so write about the environment. What did you write about this place before? What happened to it?

"White clouds are floating in the blue sky, and horses are running under them ..." This is a song that we often sing. However, with the development of science and technology, the blue sky gradually changed and became dark, just like a "gray sky". The old days were not like this.

When I was a child, my friends and I flew kites, played hide-and-seek and guessed fists on the mountain ... When we were tired of playing, we lay on the soft lawn, looked at the blue sky and made our beautiful and sincere wishes. Every breath we take is fresh and pure. Running down the mountain, talking while walking on the wide road, telling a little joke and playing a prank occasionally will often make everyone laugh. We won't worry about being knocked down, because the roads are full of bicycles that can't emit exhaust gas.

With the development of social economy, the blue sky becomes dark.

Industrial plants have mushroomed, and the chimneys on the workshops are smoking plumes of black smoke, which are scattered with the wind and emit pungent smells from time to time. They rushed into the sky unscrupulously and flew in all directions with a gust of wind. Adults say that breathing such air for a long time will lead to lung disease! Gradually, the sky became hazy, as if covered with a veil. On the road, there are more and more cars of various models. Black smoke emitted from the rear of the car forced people to breathe the unpleasant smell.

Turbid gas filled the whole sky, and the blue sky gradually darkened, losing the clarity of the past, and it was difficult for us to breathe fresh air!

Dear uncles and aunts, if you pay more attention to environmental protection when developing industry, so that factories will no longer emit smoke, the blue sky will not be sad, let alone dark!