完形填空

　　The sea is also very big. Look at a map of the world. There is more sea than land. The sea covers 1 of the world.

　　The sea is also very 2 in some places. There is one spot near Japan, where the sea is nearly eleven 3 deep. The highest mountain in the world is about 4 kilometers high. If that mountain 5 into the sea at that place, there 6 two kilometers of water above it.

　　If you 7 in the sea, you know that the sea water is salty. You can taste the salt. Rivers, 8 flow into the sea, carry salt from the land into the sea, 9 the Dead Sea, which is very salty. 10 it is very salty, swimmers can't sink! Fish can not live in the Dead Sea.

　　In 11 parts of the sea, there are plenty of fish and plants. Some live near the top of sea; 12 live deep down. There are also millions of tin living things that float in the sea. These 13 things are very small. It is hard to see them. Many fish live 14 eating them.

　　The sea can be very 15 . Divers, 16 dive deep down in the sea, know this. The top of the water may be warm. When the diver goes 17 , the sea becomes colder and colder.

　　Another thing happens, when the diver goes 18 , the water above presses 19 on him. It squeezes(压榨) him. Then the diver has to wear clothes 20 metal.

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