【正确答案】：
AS HOMONYMS ARE IDENTICAL IN SOUND OR SPELLING, PARTICULARLY HOMOPHONES, THEY ARE OFTEN EMPLOYED TO CREATE PUNS FOR DESIRED EFFECT OF HUMOR, SARCASM OR RIDICULE.
LONG TIME NO SEE IS USUALLY SAID AS A FORM OF GREETING BETWEEN TWO FRIENDS WHEN THEY MEET AFTER A LONG TIME. IN THE ABOVE CONVERSATION, BY USING SEA INSTEAD OF SEE, THE CUSTOMER CLEVERLY EMPLOYED THE STRUCTURE OF THE IDIOM TO HIS ADVANTAGE TO CRITICIZE IN A HUMOROUS WAY THE BAD QUALITY OF THE FOOD SERVED AT THE RESTAURANT. LONG TIME NO SEA IMPLIES THAT "SEA FOOD KEPT FOR A LONG TIME IS NOT FIT FOR EATING".
【题目解析】：本题考查同音同形异义词的修辞特点。由于同音同形异义词在发音或拼写上是相同的（同音异形异义词尤其如此），它们常常被用来创造双关语，以达到幽默、讽刺或嘲笑的效果。“Long time no see”通常是两个朋友久别重逢时的一种问候方式。在上面的对话中，顾客用sea代替see，巧妙地利用了这个习语的结构，以幽默的方式批评了这家餐馆的食物质量不好。“Long time no sea”意为“长时间保存的海鲜不适合食用”。