...add an extra kick at the hand entry which will help him position hips extremely high and allow him to stay right on the surface of the water...This is an excellent drill for developing body control because adding the extra kick forces the swimmer to deal with his torso and managed his body position better.
译文为,加入一次额外的打腿帮助臀居高位和使身体处于水面(注:身体不过分下沉,出水就轻松)。这个练习很好,训练你的身体控制能力