the sea
what do you know about the sea? you may have seen it. some of us have swum or bathed in it. it looks beautiful on a fine sunny day and it can be very rough when there is a strong wind. what other things do we know about it?
of course, the sea is very large. in the would there is more sea than land. the sea covers three quarters of the earth.
the sea is also very deep in some places. it is not deep everywhere; some parts of it are very shallow. but in some places the depth of the sea is very great. at one spot, near japan, the sea is nearly 11 kilometers deep! just think of it. the highest mountain in the world is only about 9 kilometers high!
if you have swum in the sea, you know that the water is salty. river carry salt from the land into the sea