Transitive verbs without objects

Sometimes transitive verbs can have their objects left out because the meaning is obvious from the context. Which of the underlined objects in these sentences can be omitted?

1. I can't find anywhere to park the car.
2. He really enjoys cooking bard.
3. They found the cat under the stairs.
4. She's been smoking cigarettes for years.
5. He slowly and carefully opened the briefcase.