Past Perfect VS Past Simple

I ……………………….(not / see) Jacob for several years, but I recognized him immediately.

The roads were blocked in the morning. It …………………. (snow) all night.

She ....................(not go) to work because she ................... (catch) a cold.

She was exhausted because she …………(work) since eight o'clock that morning.

Peter was Sally's best friend. She ……………… (know) him all her life.

We could not send you a postcard because we ............... (lose) your address.

After they ..........(see) the Tower, they........... (go) to Westminster Abbey.

Before they............... (move) to Liverpool, they............ (sell) everything.

I was delighted when I found my keys. I …………………..(look) for them for hours.

We .................. (sign) the contract before the meeting ................. (end).

(what / Bob / do)................ that he was kept in after school?

Had the teachers ……………… (work) before the strike?

John............. (play) the piano when he was a child, but he doesn't play now.