This.is.unlikely.to.be.his.book.__为什么填isn't.it而不是is.it不是前否后肯

excuse me ,whose book is this --it __ be john's .it has his Is it yours?NO,it isn't mine book.It's his.I'd like to buy a 为什么：That( )her ring.It( )his ring.中的两个括号要填isn't和is? 选词填空 This isn' my book.That is ____ book.（my,your,his,her,it Isn't it supposed to be very hot?Yes,it is.Yes,it is.怎么翻译 单项填空 1.( )-Is that ___ book?-No,it isn't .It's __ book.A.she (is.it)this a wastebasket?no.it(is.isn't ) It is't hers.It isn't his. 什么意思? whose bike is this It __ be him.His bag is on it Amust B may if the book isn"t yours,____can it be?(who else"s )为什么不填what 改正句子中的错误．1.Is it yours?No,it isn't mine book.It's his._____2 Is this your pen ? 答案是 Yes , it is.为什么No,it isn't.不对?谢谢