我花了九十年代的大部分时间环游世界。

I spent most of ___the ___nineties travelling around the world.

在九十年代，汽车污染成为一个严重问题。

In ___the ___nineties, pollution from cars became a serious issue.

许多技术进步发生在九十年代。

Many technological advancements occurred in ___the ___nineties.