this is an eraser 改复数

this is an eraser 改复数 This is an eraser 对an eraser 提问 this is an eraser 变复数.快 This is an eraser.(改为否定句) This is an eraser.(改为否定句) This is her an eraser.与This is her eraser.This is her an eraser.与This is her eraser.为什么不用“an”? This is eraser,eraser is inThis is eraser,eraser is in the pencil box.A.a;The B.an;The C.an;An D.the;The(对了,) this is an eraser in English变特殊疑问句 is this your an eraser?是不是对的， Is this your an eraser?哪错了? 英语!单数句改复数!1.He is a boy2.This is his pen3.It's an English book4.He has an eraser It is an eraser. It is an eraser? _ has an eraser .This is her eraser .横线上天什么 这句话的翻译 This it is an eraser.这个句子该用在哪,怎么用?为什么不用This ls an eraser. This is an eraser That is aThis is an eraserThat is a plate变复数句 This is ________ eraser.Is it ________ eraser?A.a,she B.an,her C.an,she D.×,her This’s an eraser and that's a card.改错误 哪里错了?并改正.