Tom: Good morning, David. What are you doing?

David: Good morning, Tom. I'm reading a book about dinosaurs.

Tom: Woo, I'm very interested in it. Let's read together.

David: Okey.

Tom: Do you know what was the biggest dinosaur?

David: Sorry, I don't know.

Tom: The biggest dinosaurs were sauropods; they were gigantic, slow moving, tiny head, cow like plant-eaters from the late Jurassic period and the early Cretaceous period.

David: Oh, I see. What about their necks?

Tom: They had very long necks which were useful for reaching wide (and tall) swatches of vegetation.

David: That's very interesting!

Tom: Yes, I have another book about Dinosaur. Shall we change it to read?

David: Sure.