帮我把英语改成否定句和一般疑问句

题目

帮我把英语改成否定句和一般疑问句
1this is an eraser
2this is your pen
3this is your pencil
4that is your ruler
5that is my ruler
6it's a pencil case

答案

否定句
1this is not an eraser.
2this is not your pen.
3this is not your pencil.
4that is not your ruler.
5that is not my ruler.
6it's not a pencil case .
一般疑问句
1 Is this an eraser?
2 Is this your pen?
3 Is this your pencil?
4 Is this your ruler?
5 Is this my ruler?
6 Is it a pencil case