TOEFL Reading: ETS-TOEFL阅读机经 - 37535R3BO8S5UP40L$

According to paragraph 1, all of the following are true of stream sorting EXCEPT: A. Most of the particles in mountain streams pile up behind boulders and cobbles. B. When particles of different sizes settle in a place, the smaller ones sit atop the larger ones. C. There are generally more large particles upstream than downstream in a river. D. In some situations, downstream particles are created from rocks that eroded as they traveled downstream.