—What are you doing, Jack?

—I’m looking for some information about the event ________ attracts all the people’s attention.

A．who

B．whose

C．which

D．whom

组成一个计算机系统的两大部分是______。

A) 系统软件和应用软件
B) 主机和外部设备
C) 硬件系统和软件系统
D) 主机和输入/输出设备