is this a backpack?（做肯定句回答）

Is this his backpack?肯定回答 Is this his backpack.(做出肯定的简略回答) 英语的题将下列各句变成否定句和一般疑问句并作简短的肯定 ,否定回答!1.This is a blue backpack. Is this his backpack （做出肯定的简略回答） Is that her nice watch（改为肯定 This is a backpack.（对.backpack提问） is this a pencil case 做肯定回答 明确句型Is this/that a/an...的肯定句回答（ ）否定回答是（ ） This is ablue backpack.(改错为否定句)This a blue backpack. this is a ruler.(对A RULER进行提问,并做肯定回答） 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. This is a pencil case?(改为一般疑问句并做肯定回答） （1）This is a red basebal (改为一般疑问句,并做肯定回答) 快,