A:4
B:3
C:2
D:1
某不纯的氯化钠样品中只含有一种杂质,取该样品11.7克,溶于适量水中,然后加入足量的硝酸银溶液,得到29.7克白色沉淀,则所含杂质不可能是( )
--- What do you think of the dress?--- Wonderful. I don't think I can find a ________ one.