Give advice to the following people

Give advice to the following people. Use I think...should or I don't think...should  and one of these phrase 
- go to the dentist   - go to work    - drive 
- write to people work so hard

1.Peter's got a very bad cold.
-.....................................
2. Ann's phone bill was enormous! Three hundred pounds!
-....................................
3. One of my teeth is loose.
-....................................
4. I'm always tired because I've been working very hard.
-...................................