在一个原本是池塘的地方出现了森林,这种群落演替属于____ .
—Which of the two subjects do you like, PE or music?—— . They are really interesting.
—Yes,____.
一瓶葡萄糖溶液,内有适量酵母菌,经测定瓶中放出的二氧化碳与消耗氧气体积之比为5:3这是因为( )