下列叙述正确的是( )
A.摩尔是物质的数量单位
B.1mol氧气的质量是32 g·mol-1。
C.CO2的摩尔质量是44g
D.0.5 mol H2SO4中含有2mol氧原子
答案:D
--- How do you find your new classmates?
----Most of them are kind, but _______ is so good to me as Bruce.
A.none
B.no one
C.everyone
D.someone
汉中的市花是()。