A.100mg/L B.200mg/L C.300mg/L D.400mg/L E.500mg/L
A.250g/LB.260g/LC.270g/LD.280g/LE.300g/L
A.四氯乙烯 B.三氯乙烷 C.氯乙烯 D.乙烯 E.乙烷