A:are exhibiting
B:is exhibiting
C:are being exhibited
D:is being exhibited
2CO(g)+O2(g)=2CO2(g)△H2=﹣566.0kJ/mol,
C(s)+0.5O2(g)=CO(g)△H3=akJ/mol,则a=____.
This story is ____ ____ ____ than that one.