Active Duty for Special Work的用法和样例：
- An old wooden box did duty for a table.
- Remark:Magnetometric sucking disc or working plateform is required for special work.
- The bench often does duty for a table.
- It's time for you to be relieved from active duty.
- In hole-measuring software, we studied the methods of digital image partition for special work piece, including classical edge-find arithmetic such as Roberts, Sobel and threshold partition .