----- Nội dung dịch tự động từ ảnh -----
46. It's not necessary for you to wear a tie here. (NEED)
47. I don't understand this Math problem. (WISH)
48. The workers want a pay increase and and so do the nurses. (NOT)
49. These are my students. Their dreams have been so big. (WHOSE)
50. They are discussing the environment pollution now, aren't they? (ABOUT)