what's this?回答是It's N .还是It's an N .为什么?

what's this?回答是It's N .还是It's an N .为什么? what's this?回答是既可用It's a...还可用This is a... What color is this apple?回答是It's green还是It's a green apple what s this回答 1.What's this/that in English?怎样回答?是It's a/an 名词 还是 It's 名词What's this/that 怎样回答?是It's a/an 名词 还是It's 名词帮个忙 what's this 回答是It's V 与 这与It's a V 有什么区别? what’s this 怎么回答? What's this回答问题 what color is this pen的回答可不可以是It's a red pen What（ )this?It's( )apple What's this?It's a box.为什么回答中要用It's,而不用this is a box What is this?It is S.为什么回答不是 It is a S. What's this it's bag.对么 -What's this?-It's a-------. What's this ( ) Chinese It's jiakeshan. 选词填空what’s this?是it’s classroom还是it’s my classroom What's this?What can it do? what's this?的回答为什么是it's… 为什么不用this is…回答如题啊……