You've received a letter from your English pen-friend in which he/she writes to you about his/her last journey and complains about his/her travelling companion. Write a letter to your pen-friend in which you tell him/her 1)where you travelled last time and who was/were your travelling companion/ companions; 2)what kind of travelling companion you prefer and why; 3)give some pieces of advice on how to avoid conflicts with a travelling companion when you travel.