There are two _____ students in my school. But our school  _____ library.[ ]

A. hundreds, doesn't have a

B. hundred, doesn't have a

C. hundreds of, doesn't have any

D. hundred, doesn't have any

计算机软件分系统软件和应用软件两大类，其中处于系统软件核心地位的是

A) 数据库管理系统
B) 操作系统
C) 程序语言系统
D) 网络通信软件