Correct such of the following expressions as need correction. If apostrophes are omitted, insert them in the proper places:
1. He walked to the precipices edge.
2. Both John and William's books were lost.
3. They sell boy's hats and mens' coats.
4. My friends' umbrella was stolen.
5. I shall buy a hat at Wanamaker's & Brown's.
6. This student's lessons.
7. These students books.
8. My daughters coming.
9. John's wife's cousin.
10. My son's wife's aunt.
11. Five years imprisonment under Texas's law.
12. John's books and Williams.
13. The Democrat's and Republican Convention.
14. France's and England's interests differ widely.
15. The moons' face was hidden.
16. Wine is made from the grape's juice.
17. Morton, the principals, signature.
18. Jones & Smith, the lawyers, office.