CH₄、H₂、CO的燃烧热分别为890.31kJ/mol、285.8kJ/mol、110.5 kJ/mol，下列热化学方程式书写正确的是

A．CH4(g)+2O2(g)=CO2(g)+2H2O(g)ΔH=-890.31kJ/mol

B．2H2(g)+ O2(g)= 2H2O(l)ΔH=-285.8kJ/mol

C．CO (g)+ H2O(g)= CO2(g)+ H2 (g)ΔH=+175.3kJ/mol

D．2CO (g)+ O2(g) = 2CO2(g)ΔH="-221" kJ/mol