Pandas are a little shy. [ ]
A. very
B. a lot
C. lots of
D. kind of
答案:D
下列有关离子方程式判断正确的是( )
A.足量铁屑溶于稀硝酸:Fe+4H++NO3-=Fe3++NO↑+2H2O
B.硫化钠溶液中通入足量硫化氢:H2S+S2-=2HS-
C.碳酸氢钙溶液中加入足量烧碱溶液:HCO3-+OH-=CO32-+H2O
D.苯酚钠溶液中通入少量二氧化碳:2C6H5O-+CO2+H2O→2C6H5OH+CO32-
A.+2价
B.+3价
C.+4价
D.+5价