光在短短几分之一秒内就能传播惊人的距离。

Light travels an incredible distance in just a ___fraction of a second.

他以几分之一秒的优势赢得了比赛。

He won the race by a ___fraction of a second.

原始手稿只有一小部分留存至今。

Only a ___fraction of the original manuscript survives today.