have an eye on的用法和样例：
- Have an eye on her .She is a novice.
- I bought ice cream,but he had an eye on beer.
- I bought ice cream, but he had an eye on beer.
- Bob visits his rich uncle every week; he's always had an eye on the main chance.
- I've had an eye on a dress in the shop for some time.
- Between you and me, we've had an eye on him for some time.
- have an eye on 密切注意(时刻提防着...