A:CH4O(l)+3/2O2(g) = CO2(g)+2H2O(l);△H= -725.8kJ/mol
B:2CH4O(l)+3O2(g)= 2CO2(g)+4H2O(l);△H= +1451.6kJ/mol
C:2CH4O+O2 = 2CO2+4H2O(l);△H= -22.68kJ/mol
D: CH4O(l)+3/2O2(g) = CO2(g)+2H2O(g);△H= -725.8kJ/mol
如图所示的四幅图中,表示近视眼成像和近视眼校正后成像情况的图分别是()
书柜里有68本书.还有多少本没看?
____ ____ ____ = ____ (本)
①y︰x= 5 ②y =x ③xy =5 ④5+x =y