我国水资源季节分配特点是( )
A:夏秋少,冬春多
B:夏秋少,冬春也少
C:夏秋多,冬春也多
D:夏秋多,冬春少
分别用以下四组物质比较Zn和Cu的金属活动性:①Zn、Cu、稀H2SO4;②Zn、Cu、MgSO4溶液;③Zn、CuSO4溶液;④Cu、ZnSO4溶液.仅用组内物质能达到目的是( )
________, I'd like to say how much I've enjoyed staying in your beautiful country.