血清白蛋白可用于治疗组织水肿、抗血小板凝集等疾病，科学家利用基因工程技术成功培育出了转基因羊，从其分泌的乳汁中可提取血清白蛋白．请回答下列问题：

甲、乙两人的住处与学校同在一条街道上，甲住处在离学校8千米的地方，乙住处在离学校5千米的地方，则甲、乙两人的住处相距（   ）

口语交际
根据上下文补全对话，将所缺少的内容写在相应的横线上
Tony: Hi, Lucy. Did you see “Jay's concert” on TV last night?
Lucy: Were they on? I didn't know about it.____?
Tony: I think it's fantastic. I clapped and cheered for Jay all the time last night. I heard that____ Beijing Theatre next Sunday.
Lucy: Is he really coming to Beijing to give a concert? Let's go and get some tickets.
Tony: ____ . There was also an interview with him, too.
Lucy: What did he say?
Tony: He said he would make a new film and hoped ____ .
Lucy: I'm sure people will like it. When will his new film be on?
Tony: He said ____ .
Lucy: Next month? I’m looking forward to seeing it now.

若b= $\sqrt{a-3}$+$\sqrt{3-a}$+2，求b^a的值．