将刻度尺的一端紧压在桌面上，拨动伸出桌面的一端会听到声音，这说明声音是由于_________产生的；显著改变刻度尺伸出桌面的长度，用与上次相同的力拨动，能够听出声音的______发生了变化；如果用_____________拨动刻度尺则可以改变声音的响度。

—Excuse me, could you tell me____________?

—There is an e–shop on the third floor. You can repair it there.

A．where can I repair my MP4 player

B．where I can repair my MP4 player

C．how can I go to the e–shop

D．how I can go to the e–shop