Answer :
1) I stayed at my sister's house.
2) Do you know Simon's phone number?
3) My brother's job is very interesting.
Basically, the idea of thesis were simplifying and shortening a sentence makes it easier to understand, that is where you should change the sentence. If it appears to make the sentence awkward, then leave it.
2) Do you know Simon's phone number?
3) My brother's job is very interesting.
Basically, the idea of thesis were simplifying and shortening a sentence makes it easier to understand, that is where you should change the sentence. If it appears to make the sentence awkward, then leave it.