阅读下面短文，根据所给情节进行续写，使之构成一个完整的故事。
It was a cold winter day.A woman drove up to the Rainbow Bridge tollbooth(收费站)．“I'm paying for myself，and for the six cars behind me，” she said with a smile，handing over seven tickets.One after another，the next six drivers arriving at the tollbooth were informed，“Some lady up ahead already paid your fare．”
It turned out that the woman，Natalie Smith，had read something on a friend's refrigerator：“Practice random kindness and senseless acts of beauty．” The phrase impressed her so much that she copied it down as soon as she got home.
