Salty water just below the surface of Mars co...

Salty water just below the surface of Mars could hold enough oxygen to support the kind of microbial （微生物的） life that existed and developed quickly on Earth billions of years ago， researchers reported on Monday.

In some locations， the amount of oxygen available could even keep alive a primitive， multicellular （多细胞的） animal such as a sponge （海绵动物）， they reported in the journal Nature Geosciences. "We discovered that brines-water with high concentrations of salt - on Mars can contain enough oxygen for microbes to breathe，" said lead author Vlada Stamenkovic， a theoretical physicist at the Jet Propulsion Laboratory in California. "This fully revolutionizes our understanding of the potential for life on Mars， today and in the past. "

Up to now， it had been assumed that the trace （微量） amounts of oxygen on the Red Planet were insufficient to sustain even microbial life. "We never thought that oxygen could play a role for life on Mars due to its rarity in the atmosphere， about 0.14 percent，" Stamenkovic said. By comparison， the life-giving gas makes up 21 percent of the air we breathe.

On Earth， aerobic-that is， oxygen breathing -life-forms evolved （净化） together with photosynthesis （光合作用）， which converts CO2 into O2. The gas played a critical role in the existence of complex life， known after the so-called Great Oxygenation Event some 2.35 billion years ago.

But our planet also holds microbes -at the bottom of the ocean， in boiling hot springs -that live in environments lack of oxygen. "That's why -whenever we thought of life on Mars -we studied the potential for anaerobic （无氧的）life，" Stamenkovic said.

1.The underlined word "insufficient" in Para. 3 means " ______ ".

A.enough B.not enough

C.wrong D.right

2.Vlada Stamenkovic may agree that ______ .

A.this research changes people's understanding of the potential for life on Mars

B.the life-giving gas makes up 31 percent of the air people breathe on earth

C.Great Oxygenation Event happened some 2.35 million years ago

D.earth holds microbial life at the bottom of the desert

3.The main idea of the passage is ______ .

A.Mars is fit for living

B.multicellular animals are living on Mars

C.oxygen plays a role for life on earth

D.Mars is likely to have enough oxygen to support life

高二英语阅读理解困难题查看答案及解析

Scientists used to explore探测on the surface of the ocean. Now they are exploring below the surface, too. They want to know about ocean water and the plant and animal life deep in the ocean.

In 1934 the scientist William Beebe dived 3 000 feet below the surface in a hollow steel ball. In 1935 August Piccard dived 10330 feet. In 1960 his son Jean dived to a depth of 35 800 feet. All these early dives were deep. But the divers could not stay down for very long. They had to come back up to the surface after a few seconds. Scientists needed to stay down longer to study life below surface. Gradually they succeeded. Cousteau, a Frenchman, was able to keep men down to a depth of 90 feet for a week.

Now scientists are developing even better equipment. With this new equipment，men can stay below the surface for days or even weeks. In 1962 Cousteau set up a research station 35 feet below the surface. Then，in 1964，he set up another station on the ocean floor of the Red Sea. This was the first undersea station to operate without help from the surface.

Many countries are now studying undersea living. The former Soviet Union has an undersea laboratory in the Crimean Sea. The United States has a laboratory 50 feet down on the ocean floor off the Virgin Islands. In 1970 five men lived there for two weeks. Then a team of five women scientists stayed in the laboratory. Next came other teams of men. All were there to explore the ocean depths and to make plans for the use of its resources. Scientists hope to find enough mineral，vegetable，and animal wealth there to provide food for the entire world.

1.In order to______ ，scientists are exploring below the surface of the ocean.

A. know about the ocean water deep in the ocean

B. stay down longer to study life of the plant and animal below the surface

C. know about the plant and animal life deep in the ocean

D. both A and C

2.Who made the deepest dive______

A. William Beebe.

B. August Piccard.

C. Jean Piccard.

D. Cousteau.

3.Which of the following statements is true____

A. The early divers could not stay down for very long.

B. Up to now only five women scientists have stayed in the undersea laboratory.

C. The purpose of setting up the undersea laboratories is to make plans for the use of the resources in the ocean.

D. None of the above is true.

高二英语阅读理解中等难度题查看答案及解析

About 97% of the world’s water is salty and is found in our oceans and seas. But, as we can’t drink sea water, how can it be important?

Every part of our seas and oceans contains an amazing number of animals and fish that live at different ocean depths. Most of the different species of animals and fish depend on simple plants for their food. These simple plants called algae (海藻) drift near the surface of the ocean and use sunlight to turn carbon dioxide and water into food and oxygen. In fact, algae produce over half of the oxygen people breathe. How important sea water is!

Each plant or animal in our seas and oceans is an important link in a food chain. The algae are eaten in large amounts by microscopic animals, which are in turn consumed by larger animals. These food chains are delicately balanced.

The bad news about the food chains in the oceans is that they are under threat because of man. People once thought that the oceans were so big that it didn’t matter if we dumped rubbish into them or caught huge quantities of fish and whales for food. But we now know this is not true and fish stocks in the oceans have started to drop.

Thankfully, the world is taking steps to protect the future of our oceans by introducing international agreements to protect marine habitats. Most countries have introduced fishing restrictions to protect fish stocks in the oceans and new techniques are being pioneered to cope with pollution. Finally, the importance of protecting oceans is being made known to more people. This is just the beginning of a long process to protect the oceans for our future. We depend on the oceans for fish which are an important part of the human diet. How important sea water is!

46. Which of the following is the proper order of the food chain?

A. small animals→algae→microscopic animals→large animals→man

B. algae→microscopic animals→large animals→larger animals→man

C. small animals→algae→large animals→microscopic animals→man

D. microscopic animals→algae→large animals →larger animals→man

47. People used to think that the rubbish thrown into the sea ________.

A. wouldn’t harm the fish in the sea   B. would change the balance of the food chain

C. would be broken down in the sea   D. wouldn’t do much harm to the sea

48. From the passage, we learn that _________.

A. most fish and sea animals live at the surface of the seas

B. it is very difficult to break the balance of a food chain

C. excessive fishing has caused the decrease in fish stock

D. it won’t be long before the problems concerning oceans will be solved

49. Which of the following is NOT a way being used to protect oceans?

A. The use of international agreements.

B. Forbidding fishing to protect fish stocks.

C. The use of new techniques.

D. Raising people’s awareness of the need to protect oceans.

50. What would be the best title of the passage?

A. The importance of seawater.

B. Life in the oceans.

C. How to protect food chains.

D. How to deal with seawater pollution.

高二英语阅读理解简单题查看答案及解析

About 97% of the world's water is salty and is found in our oceans and seas. But, as we can't drink seawater, how can it be important?

Every part of our seas and oceans contains an amazing number of animals and fish that live at different ocean depths. Most of the different species of animals and fish depend on simple plants for their food. These simple plants called algae (海藻) drift near the surface of the ocean and use sunlight to turn carbon dioxide and water into food and oxygen. In fact, algae produce over half of the oxygen people breathe. How important seawater is!

Each plant or animal in our seas and oceans is an important link in a food chain. The algae are eaten in large amounts by microscopic animals, which are in turn consumed by larger animals. These food chains are delicately balanced.

The bad news about the food chains in the oceans is that they are under threat because of man. People once thought that the oceans were so big that it didn't matter if we dumped rubbish into them or caught huge quantities of fish and whales for food. But we now know this is not true and fish stocks in the oceans have started to drop.

Thankfully, the world is taking steps to protect the future of our oceans by introducing international agreements to protect marine habitats. Most countries have introduced fishing restrictions to protect fish stocks in the oceans and new techniques are being pioneered to cope with pollution. Finally, the importance of protecting oceans is being made known to more people. This is just the beginning of a long process to protect the oceans for our future. We depend on the oceans for fish which are an important part of the human diet. How important seawater is!

1.People used to think that the rubbish thrown into the sea ________.

A．wouldn't harm the fish in the sea

B．would change the balance of the food chain

C．would be broken down in the sea

D．wouldn't do much harm to the sea

2.From the passage, we learn that ________.

A．most fish and sea animals live at the surface of the seas

B．it is very difficult to break the balance of a food chain

C．excessive fishing has caused the decrease in fish stock

D．it won't be long before the problems concerning oceans will be solved

3.Which of the following is NOT a way being used to protect oceans?

A．The use of international agreements.

B．Forbidding fishing to protect fish stocks.

C．The use of new techniques.

D．Raising people's awareness of the need to protect oceans.

4.What would be the BEST title of the passage?

A. The importance of seawater.

B. Life in the oceans.

C. How to protect food chains.

高二英语阅读理解中等难度题查看答案及解析

___ most of the earth’s surface is covered by water, fresh water is very rare and precious.

A．As               B．Although          C．If                D．Once

高二英语单项填空中等难度题查看答案及解析

By the time Dave reached the small boat, a thick white fog _______ over the surface of the water.

A. spread　　　　　　　 B. has spread

C. had spread　　　　 D. was spreading

高二英语单项填空中等难度题查看答案及解析

The old man put his oars （船桨）in the water and _______ the smooth surface of the lake.

高二英语单项填空简单题查看答案及解析

______ from the space, the earth, with water _______ seventy percent of its surface, looks like a blue ball.

A. Seen; covered　 　　 B. Seen; covering

C. Seeing; covering　　 D. Seeing; covered

高二英语单项填空中等难度题查看答案及解析

The surface of the table ______ smooth enough．

A．hash’t felt    B．isn’t feeling   C．doesn’t feel     D．isn’t felt

高二英语单项填空中等难度题查看答案及解析

___ from space, the earth with water ___70％ of its surface looks like a "blue blanket".

高二英语单项填空困难题查看答案及解析