给未受粉的番茄雌蕊柱头上涂一定浓度的生长素溶液，可获得无子番茄。说明了(　　)

下列各项属于唐朝和吐蕃密切交往的史实是（    ）

①松赞干布统一青藏高原     ②文成公主入吐蕃

③尺带珠丹与金城公主联姻   ④唐朝封怀仁可汗

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。