Replace the of-phrases by the noun in the Possessive Case1.The wife

Replace the of-phrases by the noun in the Possessive Case
1.The wife of Doctor Sandford.2.The elder sister of Helen.3.The friend of my brother-in-law4.4.The best suit of my husband.5.The novels of Dickens .6. The hat of my sister-in-law.7.The answers of the students .8.The tools of the workers .9. The dress of the girl. 10. the dresses of the girls