backpack书包: That is a backpack.那是一个书包
book书:That is a book.那是一本书
bicycle自行车:That is a bicycle. 那是一辆自行车
chair椅子:This is a chair. 这是一把椅子
desk桌子:That is a desk. 那是一张桌子
eraser橡皮: This is an eraser. 这是一块橡皮
What's this/that?这是什么/那是什么?
This/That is a/an ...这是/那是...