1、What swimming stroke are the competitors to adopt?
選手在游泳時應采用什么泳姿？

2、A swimming stroke executed with the swimmer lying on his or her back.
仰泳游泳者用仰臥姿勢進行的泳姿

3、an elementary swimming stroke imitating a swimming dog
最基本的游泳方式模仿一只在游泳的狗。

4、Any swimming stroke can be used in triathlon.
鐵人三項賽的游泳可以采用任何泳姿。