From a plane we can see the fields, （city）, mountains or seas below. If we go into space, we see more and more of the earth. People and man-made satellites have been sent out into space to look at the Earth （careful）and people have learnt more about the Earth in the last few years.
The sea looks very （ beauty）when the Sun is shining on it. But it can be very terrible when there is strong wind. The sea is very big. It nearly covers three quarters of the Earth. The sea is also very deep in some places. There is one place and at that place the sea is about 11 kilometers deep. The highest mountain in the world is about 9 kilometers high. If that mountain was put into the sea at that place, there would be still 2 kilometers of water above it! In most parts of the sea, there (be) many kinds of fishes and plants. Some live near the top of the sea. Others live deep down. There are also a lot of small living things, and lots of (fish) live by eating them. The sea can be very cold. When people go down, the sea becomes colder and colder. Only some men can go down into the deep sea. But, in 1970, five women scientists (科学家) lived in the deep sea for fourteen days.
