Why not step on the lawn?

Son, mom and dad often take you to the park to play. There is a lawn in the park, usually surrounded by railings. There is a sign inside, which says: Please don't trample on the lawn. The lawn in the park is green, like a blanket. Not only beautify the city, but also purify the air. Lawns planted in Beijing and Northeast China are mostly weeds and Leymus chinensis, and most of them are dog sprouts in the Yangtze River basin. The south likes to grow velvet grass. Due to the large urban population and little green space in China, the lawn planting area is very small. If many people trample on it, it will grow badly and even die. So please don't step on the lawn at will and tell others not to step on it. In this way, the environment around us will be cleaner and more beautiful.