An acoustically absorbent material (e. g. a fabric) may be secured to an inwardly facingsurface of any part formed from perforated sheet metal.
吸音材料(例如织物)可固定至由穿孔金属板形成的任何部分的面向内的表面。
2
Both countries arealready facing severe surface and groundwater shortages (4, 5).
目前，两国都不得不面对地表地下水短缺的严峻形势 【4 5】 。
3
Between blazing heat on the star-facing side and freezing cold on the dark side, the average surface temperature may range from minus 31 to minus 12 degrees Celsius, the researchers said.