CAXA中，块属性表中的属性数目最多不能超过（）个。
A、20
B、30
C、40
D、50
参考答案：A
Zhengzhou University has move to a new site in the western suburbs, _____ its original one. [ ]
A. large than ten times
B. more than ten times the size of
C. almost as large as ten times
D. ten times the size of
进入空压机前，空气需要进行（）级过滤。
A.一
B.二
C.三
D.四
