There is friction between the plates, so that crinkling of the upper plate occurs.

在板块之间有摩擦力，所以位于上面的那个板块会起褶皱。

youdao

There is friction between the plates, so that crinkling of the upper plate occurs.

在板块之间有摩擦力，所以位于上面的那个板块会起褶皱。

youdao