The house is dirty because it since they moved out.
—Do you think the thief entered through the window?—No, if he had, I don’t believe, _______ broken the living-room’s window.
If he ______ it, he _______ it.
If he had worked harder, he _________.
Supposing the weather ________ bad, where would you go ?
If I _______ it, I would do it in a different way.