It was quiet in the room and their silence lasted rather too long.

The silence on the other end lasted a long time.

After the silence had lasted a little while, I looked over at her.

The silence lasted for what seemed like a long time.

The silence must have lasted for two or three minutes.

The silence lasted only a minute or two, but it seemed longer.

Exactly how long the silence might have lasted is anyone's guess.

The silence lasted for half a minute; then everyone started to talk at once.

The silence only lasted a few seconds, though it felt like hours.

I had nothing to say, and the silence lasted quite a while.