Is that you pen,mary?哪里错了

Is that you pen,mary?哪里错了 what's that? That is a pen? 哪里错了?How are you? I am OK. 哪里错了 is that your pen? NO,it is. 哪里错了? Is that Mary's pen? that.is his pen哪错了 DO you want to is my pen friend?哪里错了? That's a your pen.哪里错了 can you spell a pen,please 哪里错了 My pen is in pencil case.哪里错了? This pen is Tim 判断哪里错了 What’s this?This is a pen.哪里错了? my pen is in pencil case 哪里错了?