—It ___________ great. But I ___________ tired now.

—Sam did.

How can we hear? Of course we hear sound with our ears! But do you know how our ears work?

Ask your friend to clap his hands. Cover (遮盖) your ears. Can you hear your friend clapping hands? Ask your friend to play the piano. Can you hear the sound of the piano? Cover your ears again. What can you find now?

You know that sound makes air vibrate(震动), and then it makes sound waves(声波). Before you can hear the sound, the sound waves must get to your ears.

Our ears are made up of three parts. They are the outer ear, the middle ear and the inner ear. The three parts work together.

You can see the outer ear. It collects the sound around you. Then it goes down into the middle ear and the innerwear. We can not see these two parts. But they are very important. There are hairs(绒毛) in the inner ear. The hairs help to send sound to your brain(大脑).This way, you can hear sounds around you.

Sam liked going to Mrs. Brown's with Mom. Mom was a home help. She went every day to look after Mrs. Brown's house.

She washed the dishes, made the bed, cleaned the floors, and polished the furniture.

Sam liked the house because it wasn't a bit like his own house.

He lived in a high block of flats. There, everything was new and shiny. There weren't so many closets or secret(秘密的)places.

But in Mrs. Brown's house there were lots of interesting things, and almost everything had a story.

There was a row of old china cups in a closet with a glass front. There was a shining silver（银的) bowl. There was a small box with medals which Mrs. Brown's husband had won when he was a soldier. But best of all, there was a shell(贝壳).

"l got this at the seaside when I was little. It came from Scotland. Hold it to your ear. Now, listen. If you listen very carefully, you can hear the sea."

Sam put it to his ear and listened. Sure enough, he could hear the sound of the sea.