下面的内容是 2013 年湖北高考考试卷的听力独白：
The coming next program is One Man Show by David Mellor. The guy David Mellor needs no introduction. He’s so famous, not only because of his talent, but because of his looks. Neither pretty nor ugly, they’re strange especially his face. It’s like a flat board. On the board, eyes, nose, mouth and ears are all in their places. But each of them possesses easily recognized characteristics. Take eyes for example, while they are open, what you can see are two very narrow lines. And nose, a little bit raised and shaped like a badminton bat. And his mouth is, well, let me say in this way, each corner could reach the ear, as the same goes smile from ear to ear or wear a big smile. But our guy never smiles. Actually, he doesn’t know how to smile, not to say laugh. His full and very black mustache covers his upper lip. Whenever he wants to start a speech, he bites his lips for a while. During his talk, he clears his throat from time to time. Although he pretends to be gentle, he may make you feel very tense and worried. Before I invite him onto the stage, one thing I should warn you of: listen to his talk, don’t watch his face or his show. Ladies and Gentlemen, now Mr. David Mellor.
这里的 not to say 用得对吗？是否应该用 not to mention？
not to say 和not to mention，这两个说法都有。但有不同：
not to mention，表示“递进意义”。意为“更不需要说；更谈不上”。
not to say，表示“让步意义”。意为“即便不可以说；虽不可以说…；虽说不上”。
举例说明：
not to mention，表示递进。
The audience, not to mention the bewildered cast, were not amused
观众们并没感觉好笑，更不需要说那些一头雾水的演员了。
《柯林斯高阶英汉双解学习词典》
He knows French and German, not to mention English.
他熟知法语和德语，更不需要说英语啦。
not to say，表示让步。
It is rather cool, not to say cold.
虽不可以说冷, 也算相当凉了。
《柯林斯高阶英汉双解学习词典》
I found the characters very two-dimensional, not to say dull.
我感觉，那些人物形象即便不说是乏味无聊，至少也是毫无深度。
《柯林斯高阶英汉双解学习词典》
Actually, he doesnt know how to smile, not to saylaugh.
鉴于此，网友的质疑是对的。这里表示“递进关系”，应该用 not to mention。
Actually, he doesnt know how to smile,not to mentionlaugh.
【翻译】事实上，他连微微一笑都不会，更不需要说哈哈大笑了。