E-mail systems at thousands of companies and government offices around the world were attacked by a virus(病毒)called “Melissa” that disguises(伪装)itself as an “important message from a friend. In spite of a weekend of warnings，more than 50 000 computers at about 100 places around the world have been attacked by the virus，computer security experts said on Monday.

    The virus began to show up last Friday and spread rapidly on Monday by making computers fire off dozens of infected(被传染的)e-mails. Although the virus causes no serious damage to a computer，its effect was far reaching.

    To make matters worse，a similar virus called “Papa” was discovered on Monday. Papa is programmed to send out even more infected e-mails than Melissa.

    The Melissa virus comes in the form of an e-mail，usually containing the subject line“Important Message”. It appears to be from a friend. The body of the e-mail message says，“Here is that document you asked for...,don't show it to anyone else.” Attached(附)to the message is a document file.

    Once the user opens that file，the virus digs into the user's address book and sends infected documents to the first 50 addresses. E-mails from the Papa virus include an attached spreadsheet(电子数据文件)file. When the user opens that file，the virus sends 60 infected e-mails.

    The reason why this is spreading so fast is that you are getting it from people you know. You should never open documents or attachments from people you don't know. People who get an unexpected e-mail with the “important message” subject line should delete it immediately and not open the message.

    From the loss of wildlife to rising sea levels, we're all well aware of the problems that climate change could cause.

    But while it may seem like such issues won't affect most of us directly，it looks like future generations could grow up without something that many of us now take for granted: chocolate.

    According to an essay published by the US National Oceanic and Atmospheric Administration, changes to the climate in the regions that produce cacao - the plant from which chocolate is produced - may mean that it will soon become extinct.

    Most of the world's cacao grows in countries close to the equator，with over half of it growing in the African nations of Ghana and Ivory Coast.

It's predicted that by 2050, climate change will have accelerated the rate at which temperatures in these countries rise, making it extremely difficult for cacao to grow there.

    The problem doesn't lie in increased heat, however，but in lower humidity (湿度)，as it's believed that rainfall will stay at the same level if the temperature rises.

    “In other words, as higher temperatures squeeze more water out of soil and plants, it's unlikely that rainfall will increase enough to offset the moisture (含水量) loss,” Michon Scott, the essay's author, wrote.

    To help fight this problem, researchers from Berkeley University in the US are working on changing the DNA of cacao plants to allow them to survive in dryer conditions by using gene editing technology, according to US News.

    In the meantime, US company Mars, one of the world's biggest manufacturers of chocolate products, announced in January that it would spend $1 billion to help reduce the effects of climate change.

    “This is a world issue, and it requires everyone to work together,” Mars spokesperson Barry Parkin told Business Insider.

    The message here is that if we all do our part, we may be able to prevent some of the worst impacts of climate change. Or if we're unlucky, chocolate will become a thing of the past.

    Sports can help us a lot. Taking exercises can make us strong. In collective（集体的）sports like basketball, volleyball or football, we will learn the importance of cooperation(合作). And sports can also help us relax after work or study.

    However, as the saying goes, “there are two sides of everything.” Sometimes we may hurt other players or ourselves if we are not careful enough when participating(参加) in sports activities. What's more, too much or hard practice can be bad for our health.

    Sports can make us healthy both physically and psychologically(心理地). It is also a good way for people to know each other and can improve friendship between people. So long as we are careful enough, sports can do us nothing but good.

    Growing roses is quite a difficult task without knowing the right way. If you are attracted by the beauty of roses and need some tips for growing them, read on for some tips about taking care of rose plants.

    You have to buy a good plant, preferably around two years old.

    While most rose plants can tolerate around six hours of sunlight every day, some varieties need eight hours of sunlight exposure. The shade-loving roses need only four hours of sunlight every day.

    You will have to soak (浸泡) the roots overnight before planting. If you plant them in a container, then the watering should be done daily, whereas garden roses need water once or twice a week.

    The next point is the application of fertilizer (肥料),which is mainly needed by rose plants in containers. Most of the varieties do not need fertilizer, as they can feed on the nutrients that exist in the soil. There is no need of fertilization during November and December, and the frequency of fertilization can be reduced in summer, especially after April. It can be restarted in September and has to be increased during the growing periods.

    Cutting the stems promotes the growth of the plants and also aids flowering. It should be done regularly to remove dead or diseased leaves and stems.

    Rose plants can be successfully grown by beginners too! With some care and consideration, all your efforts would definitely be worth it once you smell the fragrance of beautiful roses.

By the end of the century, if not sooner, the world's oceans will be bluer and greener thanks to a warming climate, according to a new study. 

At the heart of the phenomenon lie tiny marine microorganisms(海洋微生物) called phytoplankton. Because of the way light reflects off the organisms, these phytoplankton create colourful patterns at the ocean surface. Ocean colour varies from green to blue, depending on the type and concentration of phytoplankton. Climate change will fuel the growth of phytoplankton in some areas, while reducing it in other spots, leading to changes in the ocean's appearance. 

Phytoplankton live at the ocean surface, where they pull carbon dioxide into the ocean while giving off oxygen. When these organisms die, they bury carbon in the deep ocean, an important process that helps to regulate the global climate. But phytoplankton are vulnerable to the ocean's warming trend. Warming changes key characteristics of the ocean and can affect phytoplankton growth, since they need not only sunlight and carbon dioxide to grow, but also nutrients. 

Stephanie Dutkiewicz, a scientist in MIT's Centre for Global Change Science, built a climate model that projects changes to the oceans throughout the century. In a world that warms up by 3℃, it found that multiple changes to the colour of the oceans would occur. The model projects that currently blue areas with little phytoplankton could become even bluer. But in some waters, such as those of the Arctic, a warming will make conditions riper for phytoplankton, and these areas will turn greener. "Not only are the quantities of phytoplankton in the ocean changing, " she said, "but the type of phytoplankton is changing. "

It was 1504,and Columbus was making another trip to the New World.Columbus and his men needed fresh water and food after three months at sea.They saw an island and went to the shore.On the island there were unfriendly Indians who refused to give food and water to them.Columbus' men were afraid of the Indians,but he had a clever plan.He used gesture(手势) language to tell the Indians about his mysterious (神秘的) power to turn off the light in the sky.He knew about a lunar eclipse (月食) the next night because the information was in his almanac (天文历书).Columbus told the Indians,"Tomorrow night I'll turn off the light in the sky." But they didn't believe him.When the eclipse began the next night,the Indians became very frightened.They begged Columbus to turn on the light again,and they quickly gave him all the food and water he wanted.Immediately Columbus and his men hurried back to the ship and sailed away in the moonless night.