阅读短文，选择正确的答案。
Your Head Isn't the Right Size
The assistant: Can I help you, sir?
A man: Yes, I would like to buy a hat, please.
The assistant: Of course. How about this one?
A man: This one is too big. Would you mind (介意) bringing me a few more hats, please?
The assistant: Not at all.
A man: Let me try this one. No, I'm afraid it's too wide. What about that one? No, I'm afraid it is wide enough.
None (没有一个) of the hats is the right size.
The assistant: The hats are all right, sir. But I'm afraid your head isn't the right size.
1. The man wants to buy a . [ ]
A. hat
B. coat
C. a pair of shoes
2. The shop has hats. [ ]
A. one
B. two
C. many
3. brings him some hats, but none of them is fit.[ ]
A. The assistant
B. The doctor
C. The customer
4. The assistant says to the man " ".[ ]
A. The hats aren't the right size.
B. Your head isn't the size.
C. We have no hat.
NO（g）+6H2O（g） △H=-bkJ/mol
则N2（g）+3H2（g） 2NH3（g）的△H= ；