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