ZH
EN
JP
ES
RU
DE????? ??? ???
?? 3??? ????? ??? ???? ??? ??? ??.
?? ???? ????? ??? ???? ??? ??? ??? ????: ?? ??, ?? ??, ?? ????.
Professional Standard - Building Materials, ????? ??? ???
Professional Standard - Construction Industry, ????? ??? ???
Beijing Provincial Standard of the People's Republic of China, ????? ??? ???