Ответ:

  1. Kevin often goes to a summer camp. — Present Simple.
  2. He usually does a lot of things there. — Present Simple.
  3. Tom got a letter from his penfriend 2 days ago. — Past Simple.
  4. Karen is going to find a penfriend on the net. — to be going to.
  5. The girls will visit a dog’s shelter tomorrow. — Future Simple.
  6. Look! The cat is drinking milk. — Present Continuous.