The fire fighters ...... (put) out the fire for over three hours by the time their colleagues from San Diego have arrived.

Our neighbours ...... (clean) the windows since early morning when we come home.

The shop assistant ...... (sell) goods at the store for over twenty years when the new shop owners take over.

Mrs Hannabaum ...... (spy) for our agency for nearly five years when she retires at the end of this year.

The archaeology students ...... (look) for the artefacts for over two months when one of them finally makes a great discovery.

The general ...... (command) troops for over thirty years by the time he retires.

The office assistant ...... (do) this silly work for over four months before the boss realises that she's got a university degree in economics.

The mechanic ...... (change) the oil since late afternoon when he's finally finished.

The IT expert ...... (work) on a solution to the problem for over a week when he realises his mistake.

The men ...... (hunt) the prey for over three hours by the time they figure out where it's hiding.

The exterminator ...... (set) up mouse traps for well over an hour when he finally finds the place where the rats are hiding.

The librarian ...... (work) in the local library for almost forty years by the time she receives a good salary.

Mr Jackson ...... (persuade) the committee for over six hours before they finally give him the funds he needs.

My girlfriend ...... (write) the email for almost ten minutes by the time she realises she's got the wrong keyboard on.

The hitchhiker ...... (wait) for a ride for over two or three hours when somebody pulls up and offers him a ride.