下列各句均有一处错误, 请找出并改正。

1. My family is all at home.   ________                       _

2. What do your father do?  ________                       _

3. The girl wants be a doctor._____     _                        

4. His sister is going be a college student.________                          

5. Is your sister a teacher and a doctor?_________                          

马铃薯按植物学分类法归为（）科。