On the dawn side of the plasma sheet, the average of V_x and V_z are nearly equal to 0,but the average of V_y is in the order of -10 km/s.是什么意思_On the dawn side of the plasma sheet, the average of V_x and V_z are nearly equal to 0,but the average of V_y is in the order of -10 km/s.在线翻译_英语_读音_用法_例句