13. See you tomorrow. 明天见。 14. See you later. 待会儿见。 15. I have to go now. 我必须走了。 (二 )Expression In Class 课堂用语 16. May I come in? 我能进来吗? 17. Come in, please. 请进。 18. Sit down, please. 请坐。 19. It's time for class. 上课...