In most parts of the sea, there are plenty of fishes

and plants. Some live in near the top of the sea.

1．________

Others live deep down. There are also millions living

2．________

things that float into the sea.

3．________

Many fish lives by eating them.

4．________

The sea can be very cold. When the diver go downwards,

5．________

the sea becomes colder and colder. When the diver go deeper,

6．________

the water exerts great pressure with him.

7．________

The diver has to wear a diving suit which made of metal.

8．________

People who wants to go very deep should use a very strong

9．________

diving ship. They can even go down to a deep of 11 kilometres.

10．________