1. This treatment involves scrubbing off the top layer of dead skin. 这种治疗需要把死皮的表层除去。
2. Because of the cold temperatures, the tundra has two layers: top layer, which is called the active layer, is frozen in the winter and spring, but thaws in the summer. 由于寒冷的气温,冻土带有两层:最上面的一层被称为活动层,在冬季和春季被冻结,但在夏季解冻。
3. The top layer of skin has to be grafted onto the burns. 表层皮肤必须移植到烧伤处。
4. The top layer should now point down to the layer beneath. 顶部图层应当指向下面的图层。