From         astonished look on his face, I came to realize that he had never thought the performance would turn out to be such      great success.

A．the; a

B．the;不填

C．an; 不填

D．an; a

初中化学教学大纲（A）与新制定的义务教育化学课程标准（B）建构的内容体系分别如下：

试通过分析比较，阐述两者的特点。