cần giải thích ạ. 1. _________ to the national park before, Sue was amazed to see the tiger. A. Being not B. Not having been C. Have not been D. Having not been 2. Michael _________ be watching TV. I just saw him outside. A. mustn’t B. shouldn’t C. can’t D. might not 3. This is a valuable _________ chair which dates back to the 18th century. A. antique B. ancient C. old-fashioned D. traditional 4. How did you _________ to stop little Lisa from crying? A. help B. control C. aid D. manage 5. If you _________ Hawaii, send me a postcard. A. visited B. had visited C. will visit D. should visit