a recent fall-off in sales的用法和样例：
- To fall off in degree or intensity;subside.
- To fall off in degree or intensity; subside.
- The sale of red bean fall off considerably in the past few months.
- Jennifer: Bullshit, you've never fallen off in your whole life.
- Sales of home computers have taken off in recent years.
- They fall off in different directions from the prism over and beyond its edges.