It is crowded everywhere, the shop assistants are stressed, you have to wait for hours to pay for your goods, not to mention the time you must wait to get them wrapped.

not 是否定词，表示"不"或"没有"。 to 是不定式符号，用于连接动词原形，表示目的或意图。 mention 是动词，意思是"提到、说起"。 not to mention 是一个固定短语，意思是"更不用说"，用于引出比前面提到的内容更严重或更明显的事情。