A:汞和硝酸银溶液
B:铜和硝酸镁溶液
C:锌和硫酸亚铁溶液
D:铝和稀盐酸.
一个几何体的三视图及尺寸如图所示,则该几何体的外接球半径为( )
取甲乙两个相同的枝条,将乙的叶片全部摘除后,同时插入两个装有红色溶液的烧杯中,如图.下列分析正确的是( )
—Sorry, sir.I could have turned up on time, but I in heavy traffic.
I am playing the piano, but now the school bell is _____. ( )