Jim: Let's play volleyball, OK?
Tony: Sorry, I don't have a volleyball. But I have a basketball.
Jim: I don't want to play basketball. I only want to play volleyball.
Tony: Who has a volleyball? Do you know?
Jim: Maybe Tom has one. Let's go and ask him. （Say to Tom.）
Hi, Tom! Do you have a volleyball?
Tom: No. I don't. Does Peter have one?
Tony: Oh, yes, he does.
Tom: Hi, Peter! Do you have a volleyball?
Peter: Yes, I do. But it is at home.
Tom: Sorry to hear that!
Tony: Well, let's play basketball. OK?
Jim: OK!
Tom: Peter, please join us.
Peter: OK! Let's play!
根据对话内容，选择每个问题的正确答案。

在物理学的发展过程中，科学家们创造出了许多物理学研究方法，以下关于所用物理 学研究方法的叙述正确的是（　　）

用两平行面去截球，如图，在两个截面圆上有两个点，它们的球坐标分别为  $A(8,\frac{\mathrm{\pi }}{4},{\theta }_a),B(8,\frac{3\mathrm{\pi }}{4},{\theta }_B)$， 求出这两个截面间的距离