a modern computer system的用法和样例：
- Modern computer systems provide mass storage capabilities.
- Unfortunately solid-state memories, such as flash, that do not have these disadvantages are too expensive for stashing the vast programs needed to run a modern computer.
- They use a computer system to organize their data.
- Most modern computer systems use disks as the principle on-line storage medium, for both programs and data.
- The book has been styled in a modern format.