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DE???? ??
?? 7??? ???? ??? ??? ??? ??.
?? ???? ???? ??? ??? ??? ??? ????: ?? ? ?? ???, ??? ??, ?? ? ?? ??.
British Standards Institution (BSI), ???? ??
German Institute for Standardization, ???? ??
American Gear Manufacturers Association, ???? ??
International Organization for Standardization (ISO), ???? ??
Japanese Industrial Standards Committee (JISC), ???? ??