句型转换。 1. It's a white box. (改为复数) _________ white _________. 2. He has a short ruler. (改为一般疑问句) _________ he _________ a short ruler? 3. His father is fine . (划线部分提问) _________ _________ his father? 4. Mary has long legs. (同义句) _________ legs _________ long. 5. They're old buses. (改为单数) _________ _________ old bus.