This is an eraser 对an eraser 提问

This is an eraser 对an eraser 提问 is this your an eraser? Thay's an eraser in English.(对 an eraser 提问) I have an eraser 对an eraser提问 there is an eraser on the desk 对划线句提问 an eraser 划线 This is her an eraser.与This is her eraser. 英语对划线部分提问That is an eraser( ） （ ）this? that is( an eraser) in english.对括号内提问. 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)