By the end of August they had earned a lot of money. 

By the end of the year they had destroyed the enemy fleet

He reminded me about this event after John had left

We had burnt the dry leaves before it was snow

The rainbow appeared after the the rain had stopped

She had cut the flowers before we came to the greenhouse

Dodo is an extint kind of birds. They disappeared after people had become to hunt them.

Fire had  destroyed the building  before the firemen came. 

Mrs Marple had resolved this difficult criminal  problem before the police did it

Little Robert had spoiled the toy before his father explained him how to play with it.