题目

With both hands resting on top of the steering wheel, Oshima looks over at me: “That’s where you will be living now, Kafka. In the room where Miss Saeki used to spend time with her boyfriend. As I said, there is some change to the library, but it’s the very same room. ”        Silence on my part.     “Miss Saeki’s life stopped at age 20,when her lover died. No, maybe not age 20, maybe much earlier... I don’t know the details, but you need to know of this. The hands of the clock inside her soul stopped then. Time outside, of course, flows on as always, but she isn't affec 有这样一个试验，在一根铸铁管的一端敲一下，则在管的另一端能听到两次响声，你能解释这个现象吗？若管长931 m，两次响声相隔2.5 s，求铁管中声音的传播速度？