Respuesta:
1. When you arrive I probably will have started the job.
2. They will have had dinner by the time we get there.
3. A few centuries from now, wars, I hope, will have become a thing of the past.
4. In a year's time he will have taken some more serious sort of job.
5. You will have done a lot of your work by the end of this month.
6. By November all the leaves will have fallen.
7. If he doesn't hurry, they will have left before he comes.
8. I am sure that tomorrow you will have forgotten all these rules.
9. Be quick! The child will have drowned before you rescue it.
