Как правильно выполнить . нужно не согласиться с данными фразами. he is 3 today. he is happy today. this is my tree house. this is my sister. she is 10. my favourite food is cheese.

He isn't 3 today.
He isn't happy today.
This isn't my tree house.
This isn't my sister.
She isn't 10.
My favourite food isn't cheese.