One format is called CD-RWs. They can be recorded on and re-recorded on (rewritten on) as you would do with a floppy disk3.
有一种叫做CD - RW，是一种可反复重刻(重写)的光盘，其使用原理跟软盘一样。
2
The best way we have thought of to make the certification-level release control happen is by releasing the software on LiveCDs (CD-Rs only, no CD-RWs).