A.≤0.0010g/100ml B.≤0.0015g/100ml C.≤0.0020g/100ml D.≤0.0025g/100ml
A.≤4.0g/L B.≤3.0g/L C.≤2.0g/L D.≤1.0g/L
A.48個(gè) B.48噸 C.4722噸 D.4000個(gè)地球的重量