A:100 mL 1 mol·L-1AlCl3溶液中含阳离子数为0.1NA
B:标准状况下,1 L液态水中含有10-7NA个H+
C:一定温度下,1 L 0.5 mol·L-1NH4Cl溶液有aNA个NH4+,2 L 0.25 mol·L-1NH4Cl溶液有bNA个NH4+,则a>b
D:2 mol SO2和1 mol O2混合在盛有V2O5的密闭容器中加热反应后,容器内物质分子数等于2NA
-- It's useful for the deaf people to learn sign language.
-- Yes, it's a major way of for them.
树叶向北摆动,说明起的是( )
圆C1:x2+y2-6x+6y-46=0与圆C2:x2+y2+4x-8y-44=0公切线的条数是( )