听下面一段短文,回答第1-4小题。 1. What does the speaker want to tell us here? A. How to talk to strangers. B. How to say good-bye. C. How to please others. 2. How do English speaking people often say 'good-bye' to their workmates? A. 'See you later.' B. 'I've got to go now.' C. 'I need to clean up now.' 3. What does it mean when an American says 'I have an early class tomorrow, I need to go now.'? A. He is very busy. B. He is a student. C. It's time to leave. 4. How many countries does the speaker mention? A. Four. B. Three. C. Two.