重金属检查法中,若以硫代乙酰胺做显色剂,溶液最适pH是
A. 3~3.5 B.4~4.5 C.5~5.5 D.6~6.5 E.7~7.5
查看答案
29()
A. like
B. resemble
C. as
D. the same
30()
A. copying
B. developing
C. moving
D. charging
26()
A. stay
B. to stay
C. stays
D. staying
27()
A. to remove
B. removing
C. removed
D. remove