The oceans are unique to our planet. No other planet in our solar system has liquid water. The oceans cover about 70% of the earth's surface. They contain about 97% of the earth's water supply. Life on earth originated in the seas. The oceans continue to be home to an incredible number of plants and animals.
We know very little about the oceans. Because they are so deep and dark, they are hard to study. But scientists are discovering new strange creatures all the time. We are learning more by using satellites to look at the oceans' surfaces and by using buoys (航标 ) to measure temperature and saltiness. Special vehicles can now travel deep into the dark oceans to see what mysteries can be discovered.
More of the sun's heat is assimilated by water along the equator than at the poles. This means the water at the equator is warmer than water at the poles. These different water temperatures cause the water in the oceans to move. This is called an ocean current.
The air above ocean currents also moves. The warm or cold ocean air moves over the land as wind. Oceans are also a really important part of the water cycle. Evaporation（蒸发） from oceans creates most of the world's rainfall. Plants on land need the rain to absorb nutrients from the soil.
The oceans are also home to all kinds of sea life. These include fish, whales, dolphins, octopi, lobsters, crabs and shrimps. There are also jellyfish and starfish.Many kinds of plants, such as plankton, kelp and sea grass are part of the "forest of the seafloor."
Carbon dioxide in-oxygen out! Oceans help to capture and store carbon dioxide(C02). They are the largest natural "carbon sinks" in the world. Oceans trap about1/4of the CO2 that humans put into the air. Oceans also release oxygen. Half of the world's oxygen is produced by these tiny plants!
32.What does the author think of oceans?
A. They are amazing. B. They are common.
C. They are boundless. D. They are unimaginable.
33.What does the underlined word "assimilated" mean in the passage?
A. Taken in B. Given off. C. Cut down. D. Held back.
35.It can be inferred from the passage that____111]
A. oceans produce much carbon dioxide
B. it is not safe to live by the oceans
C. oceans provide humans with rich resources
D. humans can only depend on oceans for water