听力原文：W: At what age do children start school in your country？M: At five. How about in

听力原文：W: At what age do children start school in your country？

M: At five. How about in your country？

W: At six. Do boys and girls go to school together？

M: Yes, they do. And I think it's a good idea.

W: Do some children go on to university？

M: Yes, they do.

W: What examinations do they take first？

M: "O" levels and "A" levels.

W: Oh, but in our country they take "O" levels and "H" levels. How long do they usually stay at university？

M: Three or four years.

When do children start school in the man's country？

A．At seven.

B．At six.

C．At five.