必须具有对话功能，引用历史数据功能，引用知识库功能的系统是( )。

A．决策支持系统

B．电子数据交换系统

C．电子订货系统

D．网络加值系统

Several theories of evolution had historically preceded that of Charles Darwin, although he expounded upon the stages of development.

A．found fault with

B．explained in detail

C．outlined briefly

D．offered in published form