[问答题]
A turntable of radius+ 9unl mzn;a:kqrouyio)hq 3cmge:i: gm177 nr6y,os+ c)h3n $R_1$ 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, $\omega_1$ / $\omega_2$