[填空题]
What is the linear sp7 b-rbnap ltuig3n4r. kp9b5l )s(/b leed of a 1zjhdn2x d;1f6p 17 qe ta/vzfpoint (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? $m/s$