反弹；弹回
先理解核心含义，再看它在真实句子里的用法。
反弹；弹回
The act of rebounding or the change of direction after hitting a surface.
The ball has good bounce, perfect for basketball.
这个球弹性很好，非常适合篮球运动。
撞击地面或障碍物后运动方向的改变。
A change of direction of motion after hitting the ground or an obstacle.
弹性
the quality of a substance that is able to rebound
上下(或相反)的一次或多次运动。
A movement up and then down (or vice versa), once or repeatedly.
弹跳
a light, self-propelled movement upwards or forwards
She caught the baby on the first bounce.
她在球第一次弹起时接住了它。
The trampoline's bounce sent the child high into the air.
蹦床的弹力把孩子高高弹到空中。