句型转换 1. 昨天他不得不早起床赶公共汽车。 He get up early to catch the bus yesterday. 2. 现在我必须做作业。 I do my homework now. 3. I had to get up early yesterday.(改为否定句) I to get up early yesterday. 4. She has to clean the room every day. (改为否定句) She to clean the room every day. 5. I can dance and sing. (改为否定句) I dance sing. 6. The students can eat in the hallway.(改为一般疑问句) the students in the hallway？