a razor-sharp mind的用法和样例：
- Vast bat-like wings sprout from his back, and his long snaky tail is tipped with a razor sharp poisonous tip.
- Not only do they have a sharpened peg of a tooth but their teeth narrow down to a razor sharp edge at the back making the tigers bite much more lethal.
- I cut myself on a piece of plastic that was as sharp as a razor.
- The chess champion has a mind as keen as a razor.
- A razor should have a very sharp blade.