The Chinese remedy for poor posture is to pull your chin inward and pretend there is a string pulling straight upward from the top of your head.
中医的对不良坐姿的补救方法是向内牵引您的下巴并假装有一根从您头顶笔直向上拉的绳子。
The parrots were given the intellectually demanding task of pulling a snack on a string up to their beaks, using a co-ordinated combination of claws and beak.
鹦鹉们被分派了一项对智力要求很高的任务,它们要协调爪子和喙,将一份拴在绳子上的零食拉到它们的喙上。
And so one string must be pulling in this direction and the other string must be pulling in this direction so that the net force on the system is zero.
因此一条细绳施加一个拉力,朝这个方向,另一条细绳也必然施加拉力,朝这个方向,这样整个整体合力为零。
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