Ответ:

  1. Did you buy anything yesterday?
  2. The house’s empty. There’s nobody here.
  3. Listen. There’s somebody at the door.
  4. I’m thirsty but there’s nothing to drink.
  5. I’ve got something to drink.
  6. Hello? Is there anybody here?

Ответ: 1 — anything; 2 — nobody; 3 — somebody; 4 — nothing; 5 — something; 6 — anybody.