His or her? ???

Welches der Wörter ist richtig?

This is (Peter's) ............ rubber.
Can I have (Susan's) .......... book, please?
What is (Bill's) .......... favourite city?
Where is (Fred's) .......... calculator?
Who is (Jeanine's) ......... favourite film star?
(Karen's) ............. favourite colour is blue.
I can't see (Peter's) ........... dictionary.
(Kevin's) ............ pen is next to my ruler.
(Jack's) ............. pen is blue.
(Laura's) .............. ruler is pink.