1. It followed them, flapping double time, until it caught up, until it joined the last end of the elegant line. 它紧跟着天鹅，加倍抖动着双翅，终于赶上它们并变为了那条优美线条最后的一个点。
2. The project using mechanism structure to simulate tail fin flapping is finally put forward, which is validated by simulation. 提出用机械结构运动模拟机器鱼尾鳍拍动的解决方案，并通过仿真进行了验证。
3. As a new notional vehicle, flapping-wing micro air (FMAV) vehicle has broad application foreground and requirement of markets. 微型扑翼飞行器作为一种新概念飞行器有着广泛的应用前景和市场需求。
