20 14 Weather forecast before the Lantern Festival in Beijing: From the air quality point of view, due to small clearance and high temperature, the pollution diffusion conditions tend to be unfavorabl

20 14 Weather forecast before the Lantern Festival in Beijing: From the air quality point of view, due to small clearance and high temperature, the pollution diffusion conditions tend to be unfavorable and the pollutant concentration is rapid. Bryophytes have no differentiation of roots, stems and leaves, but there is no conducting tissue in the body, and the leaves are only composed of one layer of cells. Toxic gases such as sulfur dioxide easily invade from the back and abdomen, threatening the life of bryophytes, so we often use bryophytes as indicator plants to detect the degree of air pollution.

So choose: C.