—Look,here comes your dream girl. Invite her to dance.
—________ What if she refuses me?
A:I don't know.
B:Why me?
C:With pleasure.
D:So what?
选项
物质
所含杂质
方案
A
H2
H2O(气)
混合气体通过浓硫酸
B
KCl
MnO2
加水溶解、过滤、蒸发
C
CuO
在氧气流中加热
D
NaOH溶液
Ca(OH)2
加入过量K2CO3溶液,过滤
小胖原来有几元?
下列物质中碳元素化合价为+2价的是