Her dog is 2 years变为不定句怎么变?He is doing his homework怎么变复数句?

Her dog is 2 years变为不定句怎么变?He is doing his homework怎么变复数句? Tom is doing his homework.变成否定句怎么变? He is doing his homework .变复数...谢谢!快点啊 This is a pen变为复数句,怎么变 He is a young man 怎么变复数句 HERE IS YOUR DRESS变复数句怎么变 she is doing her homework（改为复数句）怎么改? He is in a blue t-shirt.变复数句怎么变 that is his pen变复数句 单数句变复数句,复数句变单数句1He is his friend.2Those are boxes.3 These ar the dog is big.(变复数句） he is doing his homework 改复数