[填空题]
At what distance from the Earth will aq kaiu*) :,giimgh)0 lp uo+1thw r4)y2+6ii z 6xaokr8 z(ccr spacecraft traveling directly from the Earth to the Moon experience zero net force because the zri6p +zy)wcrx4i6a8 ht1o k+2o (rcuEarth and Moon pull with equal and opposite forces? $\times 10^8$
