Practice 1　 Suppose you had a bad cold during your last trip to a famous mountain. The tourist guide has helped you a lot. Write a letter of thanks to the travel agency. Your letter should include:　 (1) a description of your case　 (2) thanks to the tourist guide and the travel agency　 You should write approximately 100 words. Do not sign your own name at the end of the letter. Use “Wang Lin” instead.