-who's that over there?-It's Lucy's sister.这里回答为什么要用It's She

-who's that over there?-It's Lucy's sister.这里回答为什么要用It's She who's that?回答到底用什么it's that's she's 要准确的 英语：who's that over there?----- ( )Jane A.She 's B.Her C It's who's singing over there?______is Sandy's sister.A That B It It's over there?为什么用over? -who's that over there? 怎么回答 英语选择题：Who's that? ( ) is Lucy. A This B It C That D She's --Who's this?--( ) is Lucy.下面四项选什么?为什么?This/It/That/She what's that over there?It's a cat,I think.Perhaps it's Li pi mother's face lighted when she saw who it was.这里为什么用lighted Who's that girl ___ my sister A This is B She is C It's D Th ( ) is a pencil.Look!It's over there.这里是填this还是that?