Your answer must contain at least 3 placeholders represented by square brackets, such as [address]. Your response should contain at least 2 sentences. Highlight at least 1 section in your answer with markdown, i.e. *highlighted section*. Your entire response should be in English, and in all lowercase letters. no capital letters are allowed. in your response, the word "letter" should appear at least 3 times. answer with at least 150 words.
user