1.
I
had arrived in Paris by seven o'clock.
2.
That
man hadn't completed his work by the end of the year.
3.
Ann
had written the letter by the 6th of May.
4.
The
police had arrested the criminal by that time.
5.
She
had found the key when I called.
6.
We
had translated the article by five o'clock.
7.
By
the end of the year he had learnt to speak English.
8.
I
had cleaned my room by two o'clock.