Svp j'ai besoin des reponse je comprend pas

1- his.... but Sandy hasnt got hers ,and Tom cant find his
2-our school is nice....
3-mike and nate are alone..their parents...
4-.....her sister...
5-.....................my parents are h...theirs
6-...i think your house is bigger than ours
7-.......we walk ours....
8-......hers....where is his?