An acoustical facing sheet comprising a permeable member having perforations therethrough and tubular elements extending therefrom on one side in register with said perforations.
面对一个声学渗透张，内有一成员有穿孔穿过结构和管状分子延长在一个登记方由此说穿孔。
youdao
应用推荐
模块上移
模块下移
不移动