Bonsoir
1- The machine (that) Dad uses is very old.
2- He's a young artist who is quite famous.
3- Don't take the books which are in my room.
4- He always helped those who were in danger.
5- The cars (that) she likes are ususally expensive.
6- Do you remenber the name of the man (that) we met at the station ?
7- Riding, which is very expensive, is a very difficult sport.
8- Did you read the ads which were in yesterday's paper ?
Les (that) ne sont vraiment pas obligatoires.... On s'en passe facilement.
bonne soirée ☺☺☺