[填空题]
What is the linear spe/ydwp ezh6wjm; /t r;-ed of a poixf(-* dqd: 1 ddlnf j5,ot4 7twmye,zsnt (a) on the equator, $m/s$ (b) on the Arctic Circle (latitude 66.5$^{\circ} $ N), $m/s$ (c) at a latitude of 45.0$^{\circ} $ N, due to the Earth’s rotation? $m/s$