this is my sister's twentieth birehday的同义句

this is a book。 it is my sister·s。用两种形式将两句合并为一句。~

This is a book of my sister's.
This book is my sister's.
This is my sister's book.

she is my aunt吧

This is the twentieth birthday of my sister.

This is my sister's birthday of twelve.

my sister was born at this day twenty years ago

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