A:pay
B:offer
C:provide
D:afford
林肯成为美国历史上受人尊敬和爱戴的总统,最主要是因为他( )
①C(s)+ 12 O2(g)═CO(g)放热110.5kJ
②CO(s)+ 12 O2(g)═CO2(g)放热283.0kJ
③C(s)+O2(g)═CO2(g)放热393.5kJ
请回答: