Nancy: Look—Mum. There are many big birds in the sky.
Mum: They're wild1. They are changing homes.
Nancy: Why do they change homes?
Mum: 2winter is coming. They cannot find food in the3in winter. So they have to fly south.
Nancy: Will they come back?
Mum: Yes. In spring, it is4in the north. They will fly back.
Nancy: Wow! They move around so much. They have busy5.
