This may be because these pupils are especially useful in perceiving objects at the relative short distances these animals tend to hunt.

这可能是因为这些瞳孔在较短的距离上感知物体特别有用，而这些动物一般近距离捕猎。

The spy preserved the same relative distance between them, and followed: with his eye upon her.

间谍在他们之间保持相同的相对距离，跟在后面：他的眼睛盯着她。

The method provided only relative distances, not absolute distances, but even so it was the first time that anyone had come up with a usable way to measure the large-scale universe.

用这种方法得到的只是相对距离，不是绝对距离。但是，即使这样，这也是第一次有人想出了一个计算浩瀚宇宙的实用方法。