—I'm looking for  M r  Black.

—He was here just now. But he _____ to a meeting and he won't be back until eleven o'clock.[ ]

A. was

B. will

C. has gone

D. has been

低渗性脱水时尿量及尿比重的变化为（）。

A.尿量正常，尿比重稍增高

B.尿量减少，尿比重明显增高

C.尿量正常或略有增加，尿比重降低

D.尿量明显增多，尿比重无明显变化

E.尿量及尿比重无变化