It is my grandmother'eightieth birthday.该句中的序数词前为何没有the

is this your mother?____ ,it is my grandmother this is my grandmother It is my grandmother's yesterday.哪错了? My grandmother is old,but your grandmother is older. my cousin's grandmother is my ____ It is my grandmother'eightieth birthday.该句中的序数词前为何没有the This is my grandmother.改为否定句 That is my grandmother.怎么变复数 my____(mother)mother is my grandmother She is my grandmother中文什么意思 My grandmother is fine.对fine提问 Where is my grandmother的意思 My grandmother is good at_(缝纫). My grandmother and grandfather is old 找错 my grandmother is good at telling s________. She is my grandmother中画线部分my grandmother.怎She is my grandmother中画线部分my grandmother.怎么对划线部分提问? Yes.This is my grandfather__________this is my grandmother. ( )A.She is my grandmother.B.She is my grandpa.