Sally: Dr. Smith, what is this?
Dr. Smith: That is a time machine, Sally.
Dr. Smith: With this machine, we can go back in time.
Sally and Tim: Wow! Can we try it?
Dr. Smith: Of course! Where do you want to go?
Tim: I want to see the dinosaurs.
Dr. Smith: No problem. Let's go!
Dr. Smith: Hop in, Tim! Hop in, Sally!
Dr. Smith: Here we are, 65 million years ago.
Sally: Wow! It looks very different.
Everything is so big.
Dr. Smith: Yes, many of the plants are very big.
Tim: Dr. Smith, I don't see the dinosaurs.
Dr. Smith: Look up.
Tim: Wow! It's huge and scary-looking.
Will it eat me?
Dr. Smith: No, it won't eat you, Tim.
It is a plant eater.
Tim: Whew! That's good.
Dr. Smith: Besides, it's only a baby.
Look over there, that is its mother.
Sally and Tim: Wow!
Sally: That dinosaur sure is big.
Dr. Smith: That is one of the biggest dinosaurs ever, Sally.
Dr. Smith: It is called a Brontosaurus.
Dr. Smith: It weighs more than 28 tons and is about 25 meters long.
Tim: I hope it doesn't step on me.
Dr. Smith: That would be very bad.
Let's explore more! But be careful.
Sally: Look at that dinosaur.
It is smaller than the other ones.
Dr. Smith: Yes, it is an Iguanodon.
It's a plant eater too.
Tim: If it's a plant eater, it won't hurt me.
Tim: Hello, Iguanodon. How are you today?
Dr. Smith: Tim, watch out!
Sally: That was close.
It almost hit you with its tail.
Dr. Smith: Yes, the Iguanodon has a very powerful tail.
Dr. Smith: It can use its tail when it is attacked.
Sally: It also uses it to hit small boys.
All: Ha-ha-ha!
Tim: Maybe we should leave it alone.
Dr. Smith: That's a good idea, Tim.
Sally: Ah! Look over there.
Look at that dinosaur.
Sally: It has a very large head.
What's its name, Dr. Smith?
Dr. Smith: It's a Triceratops.
Its head is very big and it has three horns.
Tim: Its horns look very sharp.
Dr. Smith: Yes, they are.
Dr. Smith: You can see one horn on its nose and the other two above its eyes.
Dr. Smith: It uses the horns to protect itself.
Tim: I hope it doesn't poke me.
Sally: There's a very interesting dinosaur.
Sally: It's very big, but it has a very small mouth.
I wonder how it eats.
Dr. Smith: That is a Stegosaurus.
It's a plant eater too.
Dr. Smith: You're right. It does have a very small mouth.
Tim: Look at its back. It's bumpy.
Dr. Smith: Those are called back plates, Tim.
Dr. Smith: The Stegosaurus uses them for protection.
Sally: Dr. Smith, I think that all plant eaters [n3@have some way to protect themselves.
Dr. Smith: Yes, Sally, you're right.
Tim: Look over there. What's that?
Sally: It looks like a giant egg.
Dr. Smith: Oh, don't touch it.
It's a dinosaur egg.
Dr. Smith: Soon, a baby dinosaur will hatch from it.
Sally: Really? Do all dinosaurs hatch from eggs?
Dr. Smith: Yes, they do.
Oh my! Did you hear that roar?
Tim: Why are the animals running away?
They look very scared.
Dr. Smith: That is a Tyrannosaurus.
Tim: It looks dangerous.
Dr. Smith: It is. It's a meat eater.
Tim: What does that mean?
Sally: It means we should run.
Dr. Smith: That's right! Run, Tim! Run, Sally!
Let's get out of here.
Dr. Smith: Here's the time machine. Hop in!
Come on, we have to be quick.
Sally: Oh no! Here comes the Tyrannosaurus.
Tim: Hurry, hurry, hurry!
Dr. Smith: Now, where is the "present" button?
Sally: Hurry!
Dr. Smith: I found it. Whew!
Dr. Smith: Soon we will be back in the present, safe and sound.
Tim: That was fun!
Dr. Smith, what happened to the dinosaurs?
Dr. Smith: They became extinct, Tim.
Sally: Really! How did that happen?
Dr. Smith: Some people think that a very large rock crashed into Earth.
Dr. Smith: There was a lot of smoke and dust, and then the sun went away.
Tim: Without the sun, all the dinosaurs died?
Dr. Smith: Right.
Sally: Dr. Smith, we have to go.
Our mother said to be home by five.
Dr. Smith: You had better go quickly.
Tim: Thank you, Dr. Smith. Good-bye!
Dr. Smith: Good-bye.