—How do you look after your goldfish?

—They need clean water, and remember not to _____ with your hands.

A．pick them up

B．put them out

C．look them up

D．put up them

在虚拟页式存储管理系统中，缺页中断属于( )。

A．输入输出中断

B．时钟中断

C．程序性中断

D．自愿性中断