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
设函数y=f(x),当自变量x 由x0改变到 x0+△x时,函数的改变量△y是( )
用计算器进行模拟实验,估计6人中有两人同一个月过生日的概率,在选定随机数范围后,每次实验要产生____个随机数.