I'm replaced as the subject in a sentence. What am I?

I'm placed before a noun or a pronoun in a sentence to express the ownership.

_____________name is Gloria. I'm from Brazil.

I have got a blue bike. ____bike is blue.

My parents have got good jobs but ________________ jobs are far from home.

This is my dog. _____________name is Proxy.

Look at the spider! ____________ legs are really big.

We live in the countryside. _________ garden is beautiful.

France is a wonderful country. ____________ landscapes are beautiful.

David is very rich. _____________ house is so big.

Is _______________teacher British?

Mark and Simon are friends. _________ names are in class 2.

Is ___________German?

London is famous for __________________ red buses.