A:CO2(g)+2NH3(g)CO(NH2)2(s)+H2O(g);△H<0
B:CO2(g)+H2(g)CO(g)+H2O(g);△H>0
C:CH3CH2OH (g)CH2=CH2(g)+H2O(g);△H>0
D:2C6H5CH2CH3(g)+O2(g)2 C6H5CH=CH2(g)+2H2O(g);△H<0
按要求填空