Look at the mess the boys made! You _______ have taught them how to behave themselves.

Were it not for the fact that his father is on the board of directors, he ______ the job.

— What has happened to Tom ? — I don''t know . He ____ lost . 

       for the free tickets,I would not have gone to the film so often.

(2013·哈尔滨四校高三统一检测)Look! There are so many mistakes in your composition. You ________ have fixed full attention on it.