backstrokersBNC²³⁶²¹³⁺¹ 基本例句 n.仰泳；反手击球backstroke的变形原型backstroker的复数 Great freestylers and backstrokers swim with very little central axis rotation within the upper body during the propulsive phase of the stroke. 伟大的自由泳和仰泳选手在划水的推进阶段身体上部几乎没有围绕中轴的旋转。 chinaswimming