Question - where, who, that

Correto .... OK !!!!

It's somebody who takes care of teeth
(DENTIST)

It's a plant that you can eat
(LETTUCE)

It's a place where the people pratice exercises
(GYM)

It's a thing that marks the time
(CLOCK)

It's somebody who paints pictures
(ARTIST)

It's place where there are many books
(LIBRARY)

It's somebody who works in school
(TEACHER)

It's somebody who takes care of people
(DOCTOR)

It's a machine that who use to talk
(CEL PHONE)