In many countries today, laws protect wildlife. In India, the need for such protection was realized centuries ago.

About 300 B. C., an Indian writer described forests that were somewhat like national parks today. The killing of some animals was carefully governed. Some animals were fully protected. Within the forest, nobody was allowed to cut wood for building, burn wood for charcoal (木炭), or trap animals for their furs. Animals that became dangerous to human visitors were trapped or killed outside the park so that other animals would not become uneasy.

The need for wildlife protection is greater now than ever before. About a thousand sorts of animals are in danger of extinction, and the speed at which they are being destroyed has increased. With mammals (哺乳动物), for example, the speed of extinction is now about one species every year; from A. D. 1 to 1 800, the speed was about one sort every fifty years. Everywhere, men are trying to solve the problem of protecting wildlife while caring for the world’s growing population.

C

    As shocking as the idea of baby birds growing up in a cigarette-filled home sounds, a new study suggests that some birds may benefit from putting the stuff from cigarette butts (烟蒂) into their nests. The nicotine remaining in smoked filters (滤嘴) may serve as a natural insecticide (杀虫剂), driving harmful insects away from the nests and the baby birds living within. Tobacco plants produce nicotine because it defends against insects that would otherwise eat the plants.

    The butts are undoubtedly smelly. But birds are actually quite fond of smelly chemicals, such as those found in aromatic (芳香的) plants. Some nest-building species regularly fill their nests with fresh aromatics, possibly because the chemicals are good for the immune system or the development of the chicks. Alternatively, the plant chemicals might act as insecticides.

    In the study, researchers at the Autonomous University of Tlaxeala in Mexico set up heat traps, which attract harmful insects, in 55 nests around Mexico City. Some traps were lined with the stuff in smoked cigarette filters. The others were lined with the stuff from urtsmoked cigarette filters, which did not contain nicotine and other smoking by-products. Whether the nest held eggs, chicks or nothing, the unsmoked cigarette naps collected more harmful insects, suggesting that it is the chemicals that drove harmful insects away.

    In a second experiment, the reseamhers collected 28 house sparrow nests and 29 house finch (朱雀) nests from Mexico City immediately after the chicks flew out for food. They found that the more smoked falter stuff filled a nest, the fewer harmful insects it had.

    The missing piece of the puzzle is whether the reduced number of harmful insects in the nests actually provided any benefit to the chicks. It is also unclear if nicotine or another chemical found in cigarettes may have turned the harmful insects out of the nests.

    If the results hold, then this study is an example of wildlife adaptation to urbanization —or at least evidence that birds are smart and can still follow their noses in urban environments.

C

Microsoft Windows XP support ends: How to update? If you’re still running Windows XP — what do you do now? This doesn’t mean that computers running the operating system will stop working, but it is likely that the computer will be attacked by hackers as the company stops providing security-updates and technical support for Windows XP.

Generally speaking, you have two new choices: Buy a new computer or update to Windows 7 or Windows 8.1. If you’re not ready to make a change, there are things you should do if you’ll still be on XP over the next couple of months.

Firstly, make sure the software you have is as up-to-date as possible. That means having any security fixes you can’t get from Microsoft’s website and make sure that you’ve got some (non-Microsoft) antivirus software installed(安装) from other websites. Of course, if you want to keep really safe then you’d better stay off the web altogether, though for many users this won’t even be a choice. Another choice is to change from using an administrator account to a limited account for tasks, like checking your e-mail. This means that if a hacker attacks your computer, at least they won’t have administrator-level access.

However, we have to stress that these steps are just temporary(临时的) measures and aren’t enough to protect your computer in the long run. Whether you’re buying a new computer or simply updating your present operating system depends on yourself. You’ll have to choose between Windows 7 and Windows 8.1. Whichever you go for, you’ll need to check that your computer meets the minimum system requirements for either system. For either Windows 7 or 8.1, you’ll need at least a computer with 1GB of RAM, 1GHz processor and 160GB of hard disk space. However, to run a better operating system, you’ll need a computer with over 4GB of RAM, a 2GHZ processor and 500GB of hard disk space. Buying a new computer with these functions, you may pay more than＄500.

If you’re still planning on updating, Microsoft offers some great guides on their own website, meaning that you can download your new operating system and copy all your old files without leaving your computer. Windows 7 is certainly better than Windows XP, but you should be aware that it is also an ‘old’ operating system. Microsoft Company will add more updates to Windows 8.1 over time, while Windows 7 will also come to an end before long — just like XP.

Why should mankind explore space? Why should money, time and effort be spent exploring and researching something with so few apparent benefits? Why should resources be spent on space rather than on conditions and people on the Earth? These are questions that, understandably, are very often asked．

　　Perhaps the best answer lies in our genetic makeup（基因构成）as human beings. What drove our ancestors to move from the trees into the plains, and into all possible areas and environments? The wider the spread of a species, the better its chance of survival. Perhaps the best reason for exploring space is this genetic tendency (倾向)to expand wherever possible．

　　Nearly every successful civilization(文明) has done so. In this way, any dangers in surrounding areas can be identified and prepared for. Without knowledge, we may be completely destroyed by the danger. With knowledge, we can lessen its effects．

　　Exploration also allows minerals and other potential（潜在的）resources to be found. Even if we have no immediate need of them, they will perhaps be useful later. Resources may be more than physical possessions. Knowledge or techniques have been gained through exploration. The techniques may have medical applications which can improve the length or quality of our lives．We have already benefited from improvements in earthquake prediction, in satellites for weather forecasting and in communications systems. Even non-stick pans and mirrored sunglasses are by-products（副产品）of technological developments in the space industry !

　　While many resources are spent on what seems a small return, the exploration of space allows creative, brave and intelligent members of our species to focus on what may serve to save us. While space may hold many wonders and explanations of how the universe was formed or how it works, it also holds dangers. The danger exists, but knowledge can help human being to survive. Without the ability to reach out across space, the chance to save ourselves might not exist．

While Earth is the only planet known to support life, surely the adaptive (适应)ability of humans would allow us to live on other planets. It is true that the lifestyle would be different, but human life and cultures have adapted in the past and surely could in the future．

The need to feed a growing population is putting much pressure on the world's supply of water. With 97% of the world's water too salty to be drunk or used in agriculture, the worldwide supply of water needs careful management, especially in agriculture. Although the idea of a water shortage(短缺)seems strange to someone fortunate enough to live in a high rainfall country, many of the world's agricultural industries experience constant water shortages.

Although dams can be built to store water for agricultural use in dry areas and dry seasons, the costs of water redistribution(重新分配)are very high. Not only is there the cost of the engineering itself, but there is also an environmental cost to be considered. Where valleys(山谷)are flooded to create dams, houses are lost and wildlife homes destroyed. Besides, water may flow easily through pipes to fields, but it cannot be transported from one side of the world to the other. Each country must therefore rely on the management of its own water to supply its farming requirements.

This is particularly troubling for countries with agricultural industries in areas dependent on irrigation (灌溉). In Texas, farmers' overuse of irrigation water has resulted in a 25% reduction of the water stores. In the Central Valley area of southwestern USA, a huge water engineering project provided water for farming in dry valleys, but much of the water use has been poorly managed.

Saudi Arabia's attempts to grow wheat in desert areas have seen the pumping of huge quantities of irrigation water from underground reserves.  Because there is no rainfall in these areas, such reserves can only decrease, and it is believed that fifty years of pumping will see them run dry.

Are we alone in the universe? A team of scientists announced on January 6, 2015 that they had identified eight planets beyond our solar system, three or four of which orbit in their stars' “Goldilocks Zone”—the region where temperatures are not too hot or too cold for water, which is a necessary ingredient (要素) for life as we know it, to exist in liquid form. This may be good news for people hoping that Earth is not the only inhabited world in the universe.

    The scientists, led by Dr. Guillermo Torres of the Harvard-Smithsonian Center for Astrophysics, made the discoveries using data collected by the planet-seeking Kepler telescope.

    NASA launched Kepler in 2009. Since then, the telescope has identified more than 1000 planets outside of our solar system. Torres and his team analyzed the data about the eight newly discovered worlds to determine which ones are most likely to be similar to our Earth.

    Among the new discoveries, the scientists say the planets called Kepler 438b and 442b are the closest to Earth. Kepler 438b is just about 10% larger than our planet, and gets 40% more of its energy from its star than Earth receives from the Sun. Temperatures there would be about 140 degrees. Kepler 442b is about 33% larger than Earth, but receives 30% less energy from its star. That would make it a potentially chillier world than our own. Tortes says it is possible for life to exist and survive in either of those temperatures, but for that to happen, these planets would need to have another key ingredient for life: a heat-trapping atmosphere like Earth's.

    While these findings add to the possibility that life exists beyond Earth, Tortes cautions against drawing conclusions. “We're not claiming they're inhabited,” he says. In fact these planets are so far away that the scientists cannot observe them directly, which can be explanation for why for now it remains unknown whether these planets contain life. But the discovery of planets in their stars' habitable zones suggests that somewhere out there, some form of alien life may have taken hold.

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    Back in 1969，it was the Apollo 11 crew who flew to the moon in a spaceship．When U.S. astronauts Neil Armstrong and Edwin “Buzz” Aldrin stepped foot on the moon，they were the first．Meanwhile，their fellow astronaut Michael Collins circled the moon in their spaceship，named Columbia．

    When Armstrong and Aldrin were done with their walk，they returned to the command module，and back to Earth．That part of the spaceship is on view at the Smithsonian’s Air and Space Museum in Washington，D.C. But，if you cannot get to Washington，soon you will be able to see Columbia on you computer or your smartphone．

    Digital scientists are scanning the inside of the spaceship．They are creating an online model，in three dimensions，or “3D”．By looking at these photographs，you will be able to see outer space，the way the astronauts did．It will be like sitting in their seats．

    Want your very own Columbia spaceship? You will be able to print a 3D copy of Columbia．Experts say anyone can make a life-sized model．But they expect most people to make smaller models of the 320×400cm(11’×13’)command module．

    Scientists are using special 3D technology to scan the inside．They use cameras on long arms to take the photographs．The thousands of photographs taken will be combined with 50 laser scans．

    What would it be like to sit inside Columbia and take a look around? All the images will be loaded into software that allows you to look around the module on a computer screen．The user will be able to see the Columbia both inside and out．The Smithsonian says that the 3D technology gives the user ways to see things they cannot see at the museum．And it will give information that even the museum curators(馆长)have not seen before．

    “With the Command Module，no one has been inside since it came into the collection，” says Adam Metallo，Smithsonian 3D imaging specialist．“Now the information we capture can give anyone in the world a view of what it looks like inside this incredible piece of history．”

You can not see any object unless light from that object gets into your eyes. Some of the things you see give off light of their own. The sun, the stars, a lighted lamp are examples that can be seen by their own light. Such things are luminous. Most of the things you see are not giving off light of their own. They are simply reflecting light that falls on them from the sun or some other luminous bodies. The moon, for example, does not give off any light of its own. It is non-luminous. You see it because sunlight falls on it and some of it reflects in our direction. So moon light is only second hand sunlight.

When you look at a book, it sends to your eyes some of the light which falls on it, and you see the book. If light could be kept out from where you are so that there would be no light for the book to reflect, then you could not see the book even with your eyes wide open.

Light travels so fast that the time in which it travels from the book you are reading to your eyes is so short as if there were no time at all. Light reaches us from the moon, which is about 380 000 kilometers away, in only a little more than a second.

This year’s Yulin Dog Meat Festival suffered great resistance(抵制) of dog lovers．And reports of severe conflicts between customers and dog lovers frequently appeared on the internet and newspapers．As far as dog lovers are concerned, the dog is man’s best friend．But to much wildlife，loose dogs may be a dangerous enemy，according to a study by a biologist from Utah State University in the US．

   Based on much present research and their own case studies，Julie Young of Utah State University and four other scientists conclude that loose dogs may represent a huge danger to wildlife，especially endangered species，by hunting down or worrying them and by spreading diseases．They also found that dogs，their worldwide numbers around 500 million，can cause more damage to wildlife and livestock(牲畜) than wolves and other enemies of these animals．

    Young gave examples from the US stale of Idaho，where research showed the presence of dogs reducing some deer populations．On the Navajo American Indians’ reservation in northeastern Arizona，packs of loose dogs are chasing livestock．They have killed populations of small animals such as rabbits and act as a disease carrier for rabies(狂犬病) among people and other animals，she said．Loose dogs also were to blame for distemper(犬瘟热) outbreak leading to a die off of endangered black-footed ferrets(雪貂) in northwestern Wyoming in the 1980s．

    The phenomenon does not just exist in the USA；it’s a global problem．Julie Young once studied three endangered species in central Asia；wild sheep，gazelles and antelope．The rate of injury and death to these animals by loose dogs was very high．In another case，Young found that dogs，not wolves，as originally suspected，were responsible for a large number of livestock killings in the mountainous Basque country between Spain and France．

    Authors of the study said the problem is likely to worsen as communities expand．Then how to deal with it?

    Indeed，in many countries，leash(拴狗的皮带) laws permit punishment of dog owners whose pets chase wildlife．But lawbreakers are rarely punished because the police lack both people and money．

  Young has low-cost solutions to the problem for dog lovers，though．They include public dog-training programs and vaccinating(预防接种）dogs against rabies and other illnesses.

The food chain is the order in which animals and plants eat each other in order to survive

Every living creature needs to eat other creatures below it.Every ecosystem has a different

food chain，depending on which animals and plants live there.

  The lowest part of the food chain are the plants.They are called producers because they

produce their own food using the sunlight’s energy This process is called photosynthesis.Ani-

mals are the consumers of the food chain.They eat other plants and animals.

  Some animals only eat plant.Among these are rabbits，mice and cows Some animals

eat other animals，1ike wolves，foxes or lions.

  Each food chain has a predator，the strongest animal that is not eaten by others Hawks

or polar bears are such predators.

  Many creatures belong to more than one food chain.Grass，for example,is eaten by

many other animals as well as insects.Food chains that ale connected to each other are called

food webs.

  When an animal dies it is eaten up by worms，bacteria and other organisms.These so-

called decomposers(分解者)break down animals and plants into small parts and enrich soil so

that other plants can grow better The nutrients of dead animals and plants are back to the

soil so that plants can use them again

  The balance within a food chain is determined by nature.For example，if there are too

many zebras in a tropical habitat many of them will die because they cannot get enough food to

feed on.This also means there’s less food for predators，like lions，to eat.And when there

are fewer lions the zebra population will grow again.