他在泳池边站好位置，像炮弹一样跳入水中，溅起巨大的水花。

He positioned himself at the edge of the pool and jumped in like a ___cannonballer, creating a huge splash.

那个短跑选手像炮弹一样冲过终点线。

The sprinter was a real ___cannonball, blasting past the finish line.