求翻译：有些沙发脚是木头的，有些是金属的，还有些是滑轮的，这个细节要仔细检查。主要是要结实，脚下不稳，沙发坐上去也不会舒服的。是什么意思？

Some sofa legs are made of wood, some metal, there is pulley, the details you want to double check. Mainly to strong, instability of the foot, the sofa will not be comfortable to sit.