为什么用Is this提问,却用it is回答呢

为什么用Is this提问,却用it is回答呢 What is this?提问为什么要用“It is”回答呢?可以用this is 回答吗 how is this word pronounce?为什么用is提问 用Is this 提问的选择疑问句为什么用It is 回答,而不能用This is回答例如:Is this an apple or a banana?为什么不能用This is an apple.回答?讲出道理! Is this your teacher?teather意为教师,老师.名词词性,为什么用Is this提问 为什么有些英语句子如Is this your father?要用Yes ,it is.而一些提问要用Yes,she is. Is this your sister 答语为什么要用it is. it is an ice cream.(用what提问）回答what is this?还是what is it? I find it is easy to understand American accent.为什么什么用it 不用this 或者that is that提问为什么用it回答同上 为什么“this is the first time i have baked it为什么后面用现在完成时?“i have baked it为什么后面用现在完成时? Is this your school?Yes,it is my school.Is this your ticket?Yes,this is my ticket.为什么一个用it is,一个是this is回答? Is this you pencil 为什么不能回答 yes,this is.而是要用Yes,it is. May I smoke here,please?I am afraid you ---This is a nonsmoking areaA.canB.can'tC.mayD.may notmay 提问为什么用can回答 This card is it( square)括号提问? This is my book用whose提问 this bag is green.用green提问 is this his car?否定回答时用this还是it?如果用this对吗？为什么？