This is pen变复数

This is pen变复数 this.is pen变复数句 Is this a pen?（变复数句） This is a pen变为复数句,怎么变 that is his pen变复数句 This is his pen.复数形式 this is a pen.改为复数句 This is a pen.(改为复数形式) she is a teacher.变复数 it is a pen.变复数 this is myshe is a teacher.变复数 it is a pen.变复数this is my friend.变复数的一般疑问句,并做肯定及否定回答 This si my pen pai.(变成复数形式)怎么变? This si my pen pai.(变成复数形式)怎么变? is this that 变复数怎么变 It is pen复数.和this is an eraser复数.还有he isboy复数 this is my pen pal改成复数形式 This is a pen 变为复数如题 this is my my friend(变复数) This boy is pupil（变复数) this is an eraser 变复数.快