[填空题]
What is the linear spe5n1fe ,pux t 00 lpd1lhaat:q0o iof4a0 ,bf2gw yccy8du1 z;p6*)srh )yu3 pqed of 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? $m/s$