许多游泳者更喜欢前爬泳，因为它效率高。

Many swimmers prefer the front ___crawl for its efficiency.

我会游蛙泳和爬泳，但仰泳对我来说更具挑战性。

I can swim both breaststroke and ___crawl, but backstroke is more challenging for me.

爬泳是一种游泳姿势，涉及过臂划水和鞭状踢腿。

The ___crawl is a swimming style that involves an overarm stroke and a flutter kick.