A:CO2(g)+NaOH(aq)=NaHCO3(aq) ΔH=-(2y-x)kJ·mol-1
B:CO2(g)+NaOH(aq)=NaHCO3(aq) ΔH=-(2x-y)kJ·mol-1
C:CO2(g)+NaOH(aq)=NaHCO3(aq) ΔH=-(4x-y)kJ·mol-1
D:2CO2(g)+2NaOH(l)=2NaHCO3(l) ΔH=-(8x-2y)kJ·mol-1
将“6V 3W”和“6V 6W”的两只灯泡L1和L2串联后接在电源两端,不考虑温度对灯丝电阻的影响,则( )
从小肠吸收了营养物质的血液,经过( )次心脏才能被运动全身各处.