Palmer, the British applied linguist, produced a guide to the English vocabulary needed for teaching English as a foreign language. The words are chosen for the following criteria EXCEPT______.

A．they are the words most frequently used by people whose native language is English

B．they include words useful to build other words

C．they include all the structural words

D．they include all the descriptive words

以下叙述中正确的是（）。

A．在C语言程序中，main函数必须放在其他函数的最前面

B．每个后缀为C的C语言源程序都可以单独进行编译

C．在C语言程序中，只有main函数才可单独进行编译

D．每个后缀为C的C语言源程序都应该包含一个main函数