Most Roman pottery is light and smooth to touch and very tough, although, like all pottery, it shatters if dropped on a hard surface.

大多数罗马陶器轻巧而光滑，摸起来很硬，但像所有的陶器一样，如果掉在坚硬的物质上就会碎裂。

youdao

For the light to be trapped in two dimensions, the object's surface needed to be smooth enough to cleanly reflect most of the light into the oil layer rather than scattering it at all angles.

要把光被捕获在两维的曲线状表面上时，要求物体表面非常平滑，才足以把大部分光线干净利落地反射进油层而不是分散在所有的各个角度上。

youdao

Thin wooden slats circle the unit to provide a smooth running surface to roll it and openings on the side and slated Windows let light into the interior.

它的表面环绕了一层薄木板保持表面光滑，能够使它滚动起来，在侧面开口以及预订窗户能够让外部的光线照射进来。

youdao