[填空题]
What is the linear sk- +n w8p3b4xjm,jqfo peed of1)xah*dni ufc 7gq 0(5.fkc* h(fu pjv a point (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? $m/s$