1. [单选题]关系数据库管理系统应能实现的专门关系运算包括（）.。
A. 选择、索引、统计
B. 选择、投影、连接
C. 关联、更新、排序
D. 显示、打印、制表
2. [单选题]Is a massive volume of structured and unsteuctured data so large it is difficult to process using traditional database or software technique（ ）.
A. Data Processing system
B. Big Data
C. Data warehouse
D. DBMS
