帮我把英语改成否定句和一般疑问句

问题描述:

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

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