在我年轻的时候，我每个周末都去徒步旅行。

In my younger ___days, I used to hike every weekend.

这本书写于电脑普及之前的时代。

This book was written before the ___days of computers.

在有电视之前，我们听的是广播。

Before the ___days of television, we had the radio.