下列各物质的溶液,能分别和盐酸、稀硫酸、氯化铜溶液反应并可观察到不同现象的是[ ]
A.Na2CO3
B.Ba(OH)2
C.Na2SO4
D.KOH
答案:B
Mr Smith, of the speech, started to read a novel.
A.tired; boring
B.tiring; bored
C.tired; bored
D.tiring; boring
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