One of the world's richest men has taken a close interest in one of man's most basic functions: visiting the toilet．Bill Gates’ charitable organization, the Bill and Melinda Gates Foundation, is looking for inventors to design the loo of the future, which, they hope, would improve sanitation for millions of people around the world．
So, what's wrong with the traditional flush toilet? Firstly, it wastes a huge amount of potential drinking water．Secondly, they are more likely to cause pollution．This is a real problem in many areas of the developing world, where, according to United Nations’ estimates, unsafe sanitation causes half of all hospitalizations．Younger people are particularly at risk．Illnesses which cause diarrhea are responsible for the deaths of about 1．5 million children a year．Finally, standard lavatories simply aren't practical in remote areas．
The challenge set by Bill Gates was to come up with a latrine which works without running water, electricity or aseptic tank．It also needed to operate for less than 5 cents．28 designs were displayed at the recent event of the Toilet Fair in Seattle, USA．Among them was one which turned human waste into electricity using microwaves, another which converted human waste into charcoal, and yet another which used urine for flushing．
But the winner was a solar-powered design which generated hydrogen gas and electricity．The team from the California Institute of Technology（CIT）picked up a prize of $ 100,000.
But clearly Bill Gates doesn't feel he's flushing money down the toilet．After the Seattle event he said, "We couldn't be happier with the response we've gotten," Gates has even promised $370 million more to the future toilet project．They hope to field test more prototypes over the next three years．
【小题1】Why is Bill Gates paying people to invent new toilets?

What will power your house in the future？Nuclear，wind，or solar power？According to scientists at the Massachusetts Institute of Technology (MIT) in the US，it might be leaves — but artificial (人造的) ones.

Natural leaves are able to change sunlight and water into energy. It is known as photosynthesis (光合作用)．Now researchers have found a way to imitate this seemingly simple process.

The artificial leaf developed by Daniel Nocera and his colleagues at MIT can be seen as a special silicon chip with catalysts (催化剂)．Similar to natural leaves，it can split water into hydrogen and oxygen when put into a bucket of water. The hydrogen and oxygen gases are then stored in a fuel cell，which uses those two materials to produce electricity，located either on top of a house or beside the house.

Though the leaf is only about the shape of a poker card，scientists claimed that it is promising to be an inexpensive source of electricity in developing countries. “One can imagine villages in India and Africa not long from now purchasing an affordable basic power system based on this technology,” said Nocera at a conference of the American Chemical Society.

The artificial leaf is not a new idea. The first artificial leaf was invented in 1997 but was too expensive and unstable for practical use. The new leaf，by contrast，is made of cheap materials，easy to use and highly stable. In laboratory studies，Nocera showed that an artificial leaf prototype (原型) could operate continuously for at least 45 hours without a drop in activity.

The wonderful improvements come from Nocera's recent discovery of several powerful，new and inexpensive catalysts. These catalysts make the energy transformation inside the leaf more efficient with water and sunlight. Right now，the new leaf is about 10 times more efficient at carrying out photosynthesis than a natural one. Besides，the device can run in whatever water is available；that is，it doesn't need pure water. This is important for some countries that don't have access to pure water.

With the goal to “make each home its own power station” and “give energy to the poor”，scientists believe that the new technology could be widely used in developing countries，especially in India and rural China.

1.Which of the following orders correctly shows how the artificial leaf is used to produce electricity?

a．artificial leaves split water into hydrogen and oxygen

b．the hydrogen and oxygen gases are stored in a fuel cell

c．the artificial leaves are put in water

d．the fuel cell uses hydrogen and oxygen to produce electricity

A. c，a，b，d                               B．c，b，a，d  

C．b，c，a，d                 D．c，a，d，b

2.The purpose of the scientists at MIT in developing the new artificial leaf is to________.

A．build up more power stations in the world

B．provide cheaper energy for developing countries

C．offer people in developing countries access to pure water

D．gain a deeper understanding of the photosynthesis process

3.The main idea of this passage is ________.

A．an introduction to the history of artificial leaves

B．a mixture of water power and solar energy

C．giving energy to the poor

D．an invention copying photosynthesis

Is war unavoidable? Can war be prevented?
History tells that there were wars, great or small, in every century, in every decade. Throughout the ages, from the Stone age to the Atomic Age, men have been fighting, first with swords and shields(盾), then with guns and cannons, and now, hydrogen bombs and missiles are used for military purpose. But, in spite of all these, it is still my belief that war can be prevented and peace can be won, but it requires the effort of every one of us.
I am sure that we would not like to experience another world war. If it ever happens, two-thirds of the world and much of the civilization which men have gained through time, patience and effort will be destroyed. Will then the remaining one-third of the world be able to survive on its own?
Our task now is not to blame the past, but to plan for the future.
If there is peace in the world, men can use their rockets to explore the mystery of space, their submarines to explore the depth of the sea, their missiles to deliver mails and their fine equipment to penetrate(穿透) the jungles of Africa, instead of using them military.
Governments can use their money to build more schools, so that more children can be educated to be useful citizens. Scientists can use atomic energy to propel (推动) steamships and planes. They can also design new machines to increase the production of goods and thus improve the way of living of the people.
How can a peaceful world be achieved? It requires, in my opinion, the understanding and friendship between all people from all nations. Let no one suffer discrimination by reason of color, race, religion, or national origin. Let the rich support the poor and the strong help the weak.
We know that neither peace nor such a dream world can come true in a day or a month. It may even take decades or centuries. But let us plan and begin now.
【小题1】The best title for this passage is _________.

On April 24^th, another natural disaster—the oil spill(泄露) in the Gulf of Mexico, happened．Millions of dollars have been used to help stop the spill and to clean up the animals, beaches, and land spoiled by the oil．Unfortunately, when many of these chemicals are used, more damage is caused to the environment, especially to lives in the sea．
But governments seem to accept the risk of transporting millions of tons of oil by ship every day so that we can fill up our cars and drive around and cause even more environmental damage．Interestingly, the biggest companies in the world produce cars, and the next biggest supply the gasoline to make them run.
Of all of today's environmental disasters, an oil spill may actually be one of the least serious．Although oil is poisonous, it is a natural material．In the end, it breaks down naturally．In 1967 the tanker Torrey Canyon sank off the Scilly Isles near the coast of England and spilled 120,000 tons of oil into the ocean．If you go there today, you will find it hard to see any sign that it ever happened．      
However, we should be thinking more about reducing our dependency on oil．Governments should be encouraging research into new technologies, such as cars run by solar power（太阳能）, electricity, hydrogen, and so on．Much of this research, in the past, was stopped by the oil, gas, and coal．
If the world's millions of cars were 10% more efficient（高效_{高☆考♂资♀源?网}的）,we would need many fewer tankers crossing the oceans each year．If this happened, the risks of oil spills would be reduced, and the air we breathe would be cleaner and fresher, too．
【小题1】What is the passage mainly talking about?

根据短文内容，从下边的A—F选项中选出能概括每一段主题的最佳选项。选项中有一项为多余选项。

A . The different structure of blue holes.????????

B. Why scientists are interested in blue holes.????????

C. How a blue hole comes into being.

D. Blue holes exploring is becoming popular.

E. Rules to obey when diving into blue holes.

F. The general definition of a blue hole.

1.______________

??? A blue hole is a flooded sea cave with a hole that opens up at the land's surface. These cave systems form in carbonate rock, often on islands. Some blue holes have very special rock formations and water chemistry. Far below sea level, they contain some of the harshest environments on Earth, with no oxygen and no light. Yet these areas are filled with life forms that have adapted to the extreme conditions.

2.___________

??? Blue holes get their name from the color some have when seen from the air. The color is usually a reflection of the sky on the water. Blue holes are the result of erosion in which water breaks down rock. Rain falling thousands of years ago contained chemicals which slowly wore away at the limestone landmass. These holes later filled with sea water as the sea level changed. The rising and falling of sea levels and the mixture of salt and fresh water further wore away at these cave formations.

3. ____________

??? These flooded cave systems can be found in the ocean, or they can be found inland. Ocean caves are affected by tides, so they always have water movement. But blue holes on land are very still. They have several layers of water, chemicals, and bacteria. The top layer of fresh water comes from rainfall. This layer acts like a cap on top of the layered mixture, and keeps out oxygen from the atmosphere. The fresh water floats on a denser layer of saltwater. Underneath this is a layer of poisonous hydrogen sulfide, produced by bacteria living in the water. Underneath this layer is anoxic seawater -- water that does not contain any oxygen.

4.___________

??? Information gathered from these blue holes is helping scientists to increase their understanding of biology, archaeology and geology. But exploring these blue hole environments brings danger as well as discovery. Scientists are interested in these caves because oxygen-free conditions there are similar to those on Earth long ago, before oxygen existed on our planet. But there are many difficulties involved in diving into blue holes.

5.___________

One reason blue holes have not been fully explored is that they can be extremely dangerous. There are many safety rules that divers must follow to help ensure their survival. First, divers must have training and experience to swim in these caves. Divers who explore a cave for the first time must establish a thin rope called a guideline. This line helps them to safely enter and exit the cave without getting lost.