is this your an eraser?

is this your an eraser? Is this your an eraser?哪错了? 翻译成中文IS THIS YOUR PENCIL .Yes,it`s mine.this is an eraser an This is her an eraser.与This is her eraser. This is an eraser 对an eraser 提问 This is an eraser That is a this is an eraser 改复数 this is an eraser 变复数.快 This is an eraser.(改为否定句) is this your eraser?【同义句】 A:( ) me,is this your eraser? 前面是Is this your eraser