中国第一个农村革命根据地的创建地点是()
A.南昌
B.井冈山
C.遵义
D.延安
参考答案:B
数据库镜像可以用于( )。
A.保证数据库的完整性
B.实现数据库安全性
C.进行数据库恢复或并发操作
D.实现数据共享
It was _____ problem that _____ of the students could work it out [ ]
A. so hard a; a few
B. so hard a; few
C. such hard a; few
D. such a hard; a few