this,that,is改成复数形式

this,that,is改成复数形式 this is his brother(改成复数形式） that is my sister（改成复数形式） those this is an apple.改成复数形式 Is this yuor brother改成复数形式 This is my backpack.改成复数形式 把This is a box and that is a knife.改成复数形式 Is that this watch?改为复数形式 英语啊,求救~下面的句子都改成复数形式This is my uncleIs that his friend?Is she this boy is my goog frierd改成复数形式 This is a black cat.（改成复数形式） 改成复数形式．4.This is a book. this is a beautiful cat 改成复数形式