A: 干燥氢气
B: 验证质量守恒定律
C: 检验 X 溶液中是否含有 SO 42−
D: 验证 Zn、Fe、Cu 的活动性强弱
下列关于用鼻呼吸比用口呼吸要卫生的说法中,不正确的是( )
自然地理环境改变最大的是( )
People have been complaining about SK-II recently and think the advertisements always persuade people _________ the products which are not so good. ( )