1. It's very hard to work out the math problem. (同义句) ______ the math problem is very har. 2. I would like to come to China for my vacation. (改为一般疑问句) ______ like to come to China for ______ vacation. 3. How about taking him to the Ming Tombs? (作肯定回答) ______ ______! 4. Maria has to finish her homework first. (否定句) Maria ______ ______ to finish her homework first. 5. We can explore the graves of ancient Chinese emperors. (就划线部分提问) ______ ______ we explore?