Young whales and dolphins actually rest,eat and sleep while their mother swims,towing them along in her slipstream -a placement called echelon swimming.

• 小鲸鱼和小海豚实际上是当它们的母亲在滑流中拖着它们向前游动时休息、进食和睡觉的，形成一个游泳梯队的阵形。