All surfaces inside the building should be of imperviousmaterial to permit thorough washing.
建筑里所有的表面都应当用不透水的材料这样可以彻底清洗。
2
The coal and limestone storage yard must have a bottom impermeabilization system. This system may be constituted by a clay layer, a geomembrane layer, or other imperviousmaterial.
煤料和石灰石存放场必须有底部防渗系统。该系统可由粘土层、地质处理用膜层、或其他防渗材料组成。
3
In accordance with the present invention, a liner for a hat, cap or similar head covering comprises a layer of moisture absorbent material which is backed by a layer of moisture imperviousmaterial.