to end (something) in usually an exciting or impressive way使圆满结束（或完成）
The report caps a ten-year study of lung cancer among nonsmokers.
这个报告圆满完成了对不吸烟人群患肺癌者的长达十年的研究。
— often + off in U.S. English在美国英语中常与off连用
The band capped off the show with an extended version of their classic hit.
乐队以他们风靡一时的经典曲目的延长版结束了演出。
The victory caps off the career of a coach who’s brought her team to the championships five times.
这场胜利为已率领她的运动队五次夺冠的教练的执教生涯画上了圆满的句号。