Once his forearm is perpendicular to the bottom, he pulls his laths muscles and he rotates to the other side. (前臂与池底一垂直,他就拉伸体侧肌肉并转动到另一侧)
再比如:
Any swimming practice is full of opportunities for you to get better and you just have to focus on each one until the good habits become automatic.(任何游泳练习都充满着让你游得更好的机会,你必须关注每次练习直到良好的习惯变成自动的)