Butterfly forward movement is caused by armpull and hip movement upwards.
蝶向前是靠拉臂上提臀促成。
2
There shall be no kick , armpull , or floatation that is independent of the turn.
这时将没有踢腿、划臂或者与转身无关的漂浮。
3
The head may be submerged after the last armpull prior to the touch, provided it breaks the surface of the water at some point during the last complete or incomplete cycle preceding the touch.