A:She has short straight hair.
B:She has long curly hair.
C:She has short curly hair.
如图所示,一偏心轮绕O点做匀速转动。关于偏心轮上的各点的运动,下列说法中正确的是 ( )
抽水机排水管直径2分米,排水管内水流速度为每秒钟2米.大约几小时能灌满水池?