—Could you please tell _______________________?

—Sure. Though I am a little nervous, I would love to.

A．when we shall have the graduation ceremony

B．what are you going to say at the graduation ceremony

C．where will you hold the graduation ceremony

D．if you are going to give a speech at the graduation ceremony

卫生学评价中表示声音强度大小的单位最常用的为

A．声功率级

B．声频

C．声频带

D．声压级

E．声强级