But Serena's second serve is not the fastest in the game.

但小威的第二发球并不是比赛中最快的。

Agassi’s second serve was just in.

【in】阿加西的第二次发球刚好落在界内。

Maria Sharapova, for example, will fire her second serve at about 150 kilometers per hour.

例如，玛利亚·莎拉波娃的第二发球速度将达到每小时 150 公里左右。

So, she combines the first serve, of high speed, which is a little bit more risky, but her second serve is safer.

张：所以，她的一发速度很快， 这有点冒险，但她的二发比较安全。