问题
填空题
根据句意，用括号内所给单词的正确形式填空。
1. 一I _________ (have) lunch when Bill knocked at the door.
2. He used to enjoy _________ (listen) to rock music.
3. Chinese tigers live in the south of China. They aye the _________ (old) typle of tigers living in the world.
4. The rainforests can give us a lot of _________ (use) things.
5.一Would you mind _________ (teach) me? 一Not at all.
答案
1. was having 2. listening 3. oldest 4. useful 5. teaching
畸形的病因学分类，此患者可能为（）.