this is my book.写出下列句子的复数形式

this is my book.- These are my/our books.Is that his uncle - Are those his/their uncles Is she your friend?- Are they your friends yes,it is.- Yes,they are.this is my pencil case.- These are my/our pe...O(∩_∩)O谢谢 还有道题连词成句(注意句后的标点符号)1.sister,this,your,is_________________?2.is,not,your eraser,that_______________.3.friends,his,are,those_______________?4.are,brothers,my,these_____________.谢谢1. Is this your sister ?2. That is not your eraser.3. Are those his friends ?4. These are my brothers.