Here are the answers:
10. We (recognized) Sam before he understood it.
11. Mr. Rees (has just rented) a new house and now she is there.
12. They (will have received) the money by the end of the next month.
13. Belinda (had squashed) the lemon before she started making the pies.
14. Gregory (will have insured) his flat by the end of this year.
15. Tom's puppy (has eaten) the bone and is still waiting.
16. Granny (had mashed) the potatoes before we got up.
17. My aunt (will have cancelled) the meeting by that time.
18. Mrs. Hankoff (had corrected) the text before we came
