This bag is old(变复数）急

This bag is old(变复数）急 this is he bog对he bag变复数提问 my bag is heavy.变陈述复数 This is a marker.（变复数） is this your ball?(变复数） This is pen变复数 is this that 变复数怎么变 This is a photo变复数.和 The books are in the bag对in the bag提问求了快! Is there a dictionary in your bag?(变复数句) Is this a pen?（变复数句） This is a red tomato .(变复数） this is my my friend(变复数) This boy is pupil（变复数) this.is pen变复数句 this is an eraser 变复数.快 This is her watch.[变复数】 This is a knife.怎样变复数. This child is very lovely变复数