Is it a pen?改为肯定句

Is it a pen?改为肯定句 it is his pen改为肯定句 It is a pen.改为否定句,并作肯定回答.改为一般疑问句,并作否定回答 This is a pen改为否定句,改为单复数转换改为一般疑问句或提问,肯定句做回答. Is it really a dog?改为肯定句 is it a sunny day?改为肯定句 is this a red pen 改为复数句,并作肯定回答 This is not my pen.(改为肯定句) Is it a pen 改为陈述句 it is a pen(改为一般疑问句) this is a pen.改为复数句 What's this?It's a pen.(改为复数句)