介绍:
20170620
26. Have I made myself clear? 我讲明白了吗？
27. Could you say it again? 你能再说一遍吗？
28. Any questions? 有什么问题吗？
29. That's all for today. 今天就讲到这里。
30. Please turn in your paper before leaving. 请在离开前将论文交上。
