service ace的用法和样例：
例句
- An ace is a service which cannot be reached by the opponent with his racket.
发球得分是指使对方用球拍击不到球。 - Sampras brought cheers from the crowd at Seoul's Olympic Tennis Arena as he fired down two fierce aces in his first service game.
当桑布拉斯在首尔奥林匹克网球场上开始获得两个发球得分时，场上的观众报以热烈的掌声。
