A:稀硫酸滴在铜片上:Cu+2H+═Cu2++H2↑
B:稀硫酸与Ba(OH)2溶液混合:SO42﹣+Ba2+═BaSO4↓
C:稀硝酸滴在大理石上:CaCO3+2H+═Ca2++H2CO3
D:氧化铁与稀盐酸混合:Fe2O3+6H+═2Fe3++3H2O
When I opened the fridge, there ______ only some eggs and a bottle of milk.