情景对话。
A: Hi, How 1. _____ you?
B: I am fine. Thanks.
A: 2. _____ do you 3. _____science?
B: On Tuesday morning.
A: Do you like it?
B: Yes, but my favorite 4. _____ is math. How about 5. _____?
A: Biology.
B: Why do you like,6. _____?
A: 7. _____ I can learn about many interesting things.
B: Well. But I don't 8. _____ it.
A: 9. _____?
B: Because it's difficult.
A: Let me help you 10. _____ it.
B: Thank you very much.
A: You are welcome.