Mark the sentences as O (opening remarks) or C (closing remarks). (Đánh dấu các câu là O (lời mở đầu) hoặc C (lời kết thúc).) 1. I hope you’re well. _______ 2. Write and let me know what you think. _______ 3. Don’t forget to stay in touch. _______ 4. How are you getting on? _______ 5. Drop me a line soon. _______