Fill in the gaps with the Past Perfect or the Past Perfect Continuous. . Sam (decide) that he was going to study Astronomy before he even finished secondary school.
Before she got a promotion she (not earn) enough to live comfortably.
Before they invented washing machines, people (wash) their clothes by hands for centuries.
Mary (wait) for half an hour before the bus came.
They (live) in Moscow before they moved to Stakhanov.​

Sam had decided that he was going to study Astronomy before he even finished secondary school.

Before she got a promotion she hadn’t earned enough to live comfortably.

Before they invented washing machines, people had been washing their clothes by hands for centuries.

Mary had been waiting  for half an hour before the bus came.

They had lived in Moscow before they moved to Stakhanov.​

Sam had decided that he was going to study Astronomy before he even finished secondary school.

Before she got a promotion she hadn't earned enough to live comfortably.

Before they invented washing machines, people had been washing their clothes by hands for centuries.

Mary had been waiting for half an hour before the bus came.

They had been living in Moscow before they moved to Stakhanov.