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
A month had passed, but the government didn't find the________of the mine accident.
下列国家中,从事制造业的人口比例最高的是( )
He ________having been frightened.
计算: (3+2)3×(3-2)3=____ .