几道物理

awaawaUID: 2224051

A speaker plays a loud, constant tone. How does a listener, riding a bicycle toward the speaker, perceive the sound?


  
  (A) The listener hears a higher frequency of sound wave than that produced by the speaker.  
(B) The listener hears a higher amplitude of sound wave than that produced by the speaker.  
- q! M( ]$ }- k (C) The listener hears a longer wavelength of sound than that produced by the speaker.  
(D) The listener hears a lower frequency of sound wave than that produced by the speaker.  
(E) The listener hears a lower amplitude of sound wave than that produced by the speaker.  

( y% R2 e' n$ s7 Q( Z. Z不是品率升高吗？怎么不选a呢

suimongUID: 2256015

恩，我也觉得这题的答案有问题……应该是a吧……

water0915UID: 2222422

那是什么答案?