And we're supposed to believe that can track one of them?

这么说我们应该相信那个玩意能够追踪出他们？

First, they must find the arrow shaft. It will show them which tracks to follow and also who made the hit.

首先他们要找到箭，它能指示出追踪方向并能确定是谁射中了猎物。

A quick survey of current diseases lets us trace out four stages in the evolution of a specialized human disease from an animal precursor.

对当前疾病调查让我们能够追踪出从动物前身到人类特殊疾病进化四个阶段。