He can speak French German and Russian English.　A. not mentioning　B. no mentionC. not

问题补充：

He can speak French, German, and Russian, English.

A. not mentioning

B. no mention

C. not to mention

D. not to be mentioned

答案：

A. not mentioning

B. no mention

(答案→)C. not to mention

D. not to be mentioned

解析：考查固定短语。not to mention更不用说，更不消说。句意：他会讲法语，德语和俄语，更不用说会讲英语了。所以选C。