Dear Callie, It has been a fun, exciting vacation. The tour guide who has become a good friend is great! I think you would have loved this trip because you love excitement. After I get home, we should plan a trip together. Sincerely, Julia Which of the sentences in the letter contains a comma error? It has been a fun, exciting vacation. The tour guide who has become a good friend is great! I think you would have loved this trip because you love excitement. After I get home, we should plan a trip together.