my sister name变复数

my sister name变复数 This is my sister?怎么变复数形式?代词my用变复数吗? my sister's name This is my sister.改为复数形式、 This is my sister(变为复数句) That is my sister改为复数形式 this is my my friend(变复数) my name is jack 变特殊疑问句 she is my sister.变否定句怎么变 She is my friend.变复数句 Here is my family photo 变复数 That is my grandmother.怎么变复数 My cousin is a postman变复数 it is my foot 变复数 my bag is heavy.变陈述复数 It is my boot .变复数 把these are my ruler改为一般疑问句后是什么?还有这几道题：this is her sister(变复数形式）that is my dictionary(变为复数形式)those are his books(变为单数） Thsae are his brothers（变单数形式） That's his friend（变复数形式） Is this your sister?(做否定回答) Those are my friends,(变单数形式)