数据中心从功能上可以分为计算机房和（）。
A.存储机房
B.网络机房
C.运营机房
D.其他支持空间
参考答案：D
— He can't have finished his homework last night, ______ he?
— No. You see, he is busy doing it now. [ ]
A. has
B. may
C. can
D. did
中国面临的环境污染种类包括：水环境污染、（）、（）、噪音污染；
