Our foreign trade policy has always been based on equality and mutual benefit and exchange of needed goods.
我们的对外贸易政策一向是以平等互利、互通有无为基础的。
If we could actually see the path described by a particle,such as a sand grain in the rock,
假如我们真能看到的运动轨迹,诸如岩石中一个沙粒分子