THE POSSESSIVE CASE ( 'S / ' )

Doris's ice cream is delicious

Lucy's ice-cream is strawberry

Try  These links for some exercises

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-4640.php

https://english.lingolia.com/en/grammar/nouns-and-articles/possessive-case/exercises/articles/possessive-case-of-nouns-mixed-exercise

http://www.ego4u.com/en/cram-up/grammar/nouns/exercises?04

http://www.wijng.com/de/en/exercise-fill_in.htm?lessonID=43&exerciseID=127