What do know about the sea? Some people have seen it but others haven't. The sea looks beautiful on a fine sunny day and it can be very tough when there is a strong wind. What other things do you know about it? Of course, the sea is very large. In the world there is more sea than land. If you have swum in the sea, you know that the sea is salty.

　　Rivers carry salt from the land into the sea. Some places of the sea are saltier than the other places. Do you know the Dead Sea? It is so salty that you can’t sink when you are in the water! And fish cannot live in it!