数据库通常是指有组织地、动态地存储在();应用数据库的主要目的是解决数据()问题。
应用数据库的主要目的是解决数据()问题。
A.保密
B.完整性
C.一致性
D.共享
参考答案:D
—Tom didn't go to school this morning, did he?
—_____, though he was not feeling very well. [ ]
A. No. he didn't
B. Yes, he did
C. No, he doesn't
D. Yes, he does
安全阀用于流体管道或重要设备上,当流体压力超过()时,安全阀起跳,流体从管道或设备内进行放散。
A.操作压力
B.安全阀定压值