[填空题]
What is the linear speed6 qc vmb0 4f)g 06z0vuxkbc+6d qhhnx, of a 1pcv5 ph e(1 sej2iiq8point (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? $m/s$