rapid和quick还有fast最大是什么区别？

rapid
/ ˈræpɪd; ˋræpɪd/ adj
(a) moving or acting with great speed; fast 迅速的; 快的: a rapid pulse, heartbeat 过快的脉搏、 心搏 * ask several questions in rapid succession 快速连续提出几个问题 * the rapid to-and-fro movements of a piston 活塞快速的往复运动. (b) happening in a short time; prompt 短时间内发生的; 敏捷的: a rapid decline in sales 销售额的急剧下降 * Cats have rapid reflexes. 猫的反应很敏捷.
(of a slope) descending steeply （指斜坡）陡的.
(idm 习语) make great/rapid strides => stride n.
> rapidity / rəˈpɪdətɪ; rəˋpɪdətɪ/ n [U].
rapidly adv.
rapids n [pl] swift current in a river caused by a steep downward slope in the river bed （河的）急流, 湍流: shoot the rapids, eg in a canoe 穿过急流（如乘独木舟）.
# rapid-fire adj [attrib 作定语] (a) (of a gun) firing bullets, etc in quick succession （指枪炮）速射的. (b) (fig 比喻) (of questions, etc) spoken very quickly, one after the other （指问题等）连珠炮似的: the rapid-fire jokes of a comedian 喜剧演员连续说出的笑话.