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DE? ??? ??
?? 7??? ? ??? ??? ??? ??? ??.
?? ???? ? ??? ??? ??? ??? ??? ????: ?? ??, ??????, ??? ? ??? ??.
Professional Standard - Geology, ? ??? ??
Professional Standard - Electricity, ? ??? ??
Professional Standard - Aerospace, ? ??? ??
Group Standards of the People's Republic of China, ? ??? ??