A:向苯酚钠溶液中通入少量CO2:2C6H5O—+ CO2 +H2O → 2C6H5OH+CO32-
B:用铜为电极电解稀硫酸溶液: 2H2O O2↑+ 2H2 ↑
C:碳酸钙与醋酸反应:CO32-+2CH 3COOH = CO2↑+ H2O+2CH3COO—
D:Ba (OH)2溶液中加入过量Al2(SO4)3溶液:
(____)I don't know.
(____)Where is my pencil?
(____)Li Hua, Where's your pencil?
(____)There it is.
(____)Danny, where is my pencil? Can you see it?(你看见它了吗?)
长征是充满着无私奉献精神的史诗。无论是山势逶yí____的五岭山,还是气势磅bó____的乌蒙山;无论是泥泞____草地,还是悬崖峭____壁;无论是酷暑严寒,还是饥饿干渴……红军将士都抱定全心全意为人民服务的宗旨,以坚忍不拔的毅力坚持到底。
已知:实常数a、b、c、d同时满足下列两个等式:①asinθ+bcosθ﹣c=0;②acosθ﹣bsinθ+d=0(其中θ为任意锐角),则a、b、c、d之间的关系式是:____