Change from past perfect active into past perfeeect passive.
I couldnt geet into the hourse as I had lost the key. The key had been lost.
By the time my mom ceme I had cleaned my room. My room....
By 7 oclock I had done my morning exercises. Morning exercises....
Before we went out the teacher had checked our test. Our tests....
He was happy that he had found his watch. His wach....