[问答题]
A turntable of radiu)o yd k )hv*0tzjs(,q1d4bar4fg hk, fs qkat1 z+i 8-6 plfc8twbvm4j0 $R_1$ is turned by a circular rubber roller of radius $R_2$ in contact with it at their outer edges. What is the ratio of their angular velocities, $\omega_1$ / $\omega_2$