A:C8H18(l)+12.5O2(g)='=' 8CO2(g)+ 9H2O(g)ΔH= —48.40KJ/mol
B:C8H18(l)+12.5O2(g)='=' 8CO2(g)+ 9H2O(l)ΔH= —5518KJ/mol
C:C8H18(l)+12.5O2(g)='=' 8CO2(g)+ 9H2O(l)ΔH= +5518KJ/mol
D:C8H18(l)+12.5O2(g)='=' 8CO2(g)+ 9H2O(l)ΔH= —48.40KJ/mol
唐朝政局可用下图表示,下图中“?”处应为( )
下列行为中有利于建设良好班集体的是( )
一面镜子竖直悬挂在墙壁上,人眼睛的位置如图所示,现在甲乙丙三个物体放在镜子面前,则人眼能通过镜子看到像的物体有( )