懂英语帮忙看一下 都是很简单的 再线等!

懂英语帮忙看一下 都是很简单的 再线等!
选词填空
The _____ _____ records information.
The _____ helps you control the computer.
The _____ _____ contains all the computer's electronics.
We put _____ into the _____ in the main unit.
mouse(鼠标) drives(驱动) floppy dish(软盘) main unit(主机) CD-ROM(光驱)
汗..最后一个是怎样吖 ...?? 确定百分百对的才告诉我哦!!!