a fifteen-stroke rally的用法和样例：
- We will now have a fifteen minute recess after this lesson.
- Which do you think is better as a gift for a fifteen year old girl?
- At the prices you gave me,a fifteen percent discount would be good.
- Do you prepare to make a fifteen percent down payment?
- The mass rally was a total fiasco.
- Nightfall left exhausted fire-crews facing flames on a fifteen mile front.