racing backstroke竞技仰泳
backstroke swimmer仰泳运动员
BS Backstroke仰泳
Basic Backstroke基本仰泳
crawl backstroke仰泳
backstroke e仰泳;仰式
backstroke detail反手拍击
mid backstroke仰泳中
backstroke race仰泳
N-UNCOUNT（不可数名词） Backstroke is a swimming stroke that you do lying on your back. 仰泳 [also 'the' N]
"I see you know how to swim very well," she said, watching him do the backstroke.
“看来你很会游泳啊”，她一边说一边看他仰泳。