4000，7，1，30，5，9
—Excuse me. Could you tell me ________?
— Sorry, I am new here.
A．where the hospital is
B．where is the hospital
C．where the hospital was
D．where was the hospital
一球形石英颗粒，在空气中按斯托克斯定律沉降，若空气温度由20℃升至50℃，则其沉降速度将（）。
