Christian Eijkman, a Dutch doctor, left the Netherlands for the island of Java. Many people on the island had a disease called beri-beri. He was going there to try and find a cure.

    At first, Eijkman thought some kind of germ (细菌) caused beri-beri. He raised some chickens. He didn't eat them, but made experiments on them. The local people were quite surprised at that. One day he noticed that his chickens became sick when they were fed the food most Javanese ate — refined white rice (精炼米). When he fed them with unrefined rice, also known as brown rice, they recovered. Eijkman realized that he had made an important discovery — that some things in food could prevent disease. These things were named vitamins. The Javanese were not getting enough vitamins because they had actually removed the part that contains vitamins. Later, other diseases were also found to be caused by the lack of vitamins in a person's food.

    Today many people know the importance of vitamins and they make sure they have enough vitamins from the food they eat. If they don't, they can also take vitamin pills.

    Great speakers are not born but made. You too can become a good orator by taking up the public speaking courses. Those who are incapable of speaking in front of the public can't come up in their life. The art of public speaking must be practiced by everybody who wants to reach great heights in their career. A lot of public speaking courses are available on the Internet. Choosing the best course that is right for you may be difficult but not impossible.

    The basic motive of public speaking courses should be to train you to become a public speaker and improve your skills of delivering a public speech. The course should first educate you with the principles of public speaking and tell you how to overcome stress and anxiety. By overcoming fear, you will be able to deliver your presentation clearly to your audience.

    A speaker can have a great influence on the audience with his body language and your public speaking course should tell you the gestures on stage that can attract the audience. Non-verbal communication also has a major role to play in delivering a speech effectively to a group. Though body language is important, the content and the natural use of words are what the audience are closely caring about. Public speaking courses should give tips in using the right words at the right time.

    Even though you have prepared well, the real success of public speaking lies in the way your speech is delivered. Public speaking courses will train you to present the contents in a lively manner impressing the audience. Your presentation should be professional and stylish. You can add humor or interactive sessions (互动环节) to your presentation to gain the audience attraction.

Venom(毒液）from a local scorpion(蝎子）in Cuba is being used by Cuban scientists as an effective weapon to fight cancer. The venom, with stopping pain, anti-inflammatory (炎症） and anti-cancer properties, is the active ingredient in the medicine “Vidatox 30 CH“ which can be used to treat liver, brain, lung and other cancers. The treatment has been successfully used for more than four years in humans after being first tested in biological models. Labiofam, a Cuban laboratory, has breeding(繁殖)centers for both the Red Scorpion and Blue Scorpion. Each month, some 30,000 scorpions in Las Minas town, 270 km east of Havana are made to give the venom. After two years, the scorpions are released back into their natural habitat.

Denyer Sanchez, a biologist from Labiofam, explained that the conditions are adjusted for reproduction, proved by the high number of breeding female scorpions. He said when the offspring(后代）becomes able to live in the environment, we release them because they do not have the necessary size yet to remove their venom, said Sanchez. Sanchez also said that there is still much to research on the exploitation process of scorpions, such as female death rate or the ability to survive of the released scorpions.

Cuban research on the scorpion's venom began at the end of 1980s in Guantanamo province, the island's eastern tip, where a group of biologists and doctors became interested in the stories told by the peasants about the venom's benefits. However，the first discovery was made by Cuban biologist Misael Bordier. In 2001, Bordier visited Mexico's National Autonomous University (UNAM) and presented the research progress in a professional journal. Bordier died in 2005, one year before Cuba's Industrial Property Office gave Labiofam the rights to exploit the patent related to the venom.

    In the middle of the 19th century，a fever dream of riches beyond measure drew countless explorers west to the mountains of central California. Although the gold rush ended up being a bust for many who sought a fortune，some of those explorers discovered a natural treasure that would draw permanent settlers to Yosemite Valley in the following decade.

    Vast wilderness，beautiful mountains，countless waterfalls，and abundant wildlife drew Native Americans to Yosemite roughly 10，000 years ago. The first non-native tourists arrived in the mid-1850s after reports from gold seekers told of an area of breathtaking beauty that no words were able to describe.

    Fortunately，some of Yosemite's earliest settlers recognized that Yosemite's natural beauty and resources needed to be preserved for future generations. In the midst of the Civil War，President Abraham Lincoln signed a grant to protect Yosemite permanently，thus making it the nation's first land to be dedicated to recreation and setting the stage for what would become the national park system.

    One of Yosemite's earliest ambassadors was Scottish-American naturalist and writer John Muir. After living in Yosemite for a few years，he helped define its proposed boundaries. He also wrote articles that helped lead to its official title as a National Park in 1890.He later co-founded the Sierra Club in 1892 to advocate for its continued preservation and protection.

    Located on the western slope of the Sierra Nevada mountain range in central California，Yosemite National Park runs across nearly 748，000 acres，almost 95％of which is wilderness. Around four million visitors come to Yosemite each year to camp，hike its miles of trails，climb its rock formations，and photograph its impressive sights. Are you ready to visit Yosemite National Park? Which of Yosemite's sights would you most like to experience?

    Recently, a 1935 letter in which Ernest Hemingway detailed his catch of a 500lb blue marlin(青枪鱼), an adventure that is believed to have partly inspired his novel The Old Man and the Sea, has been sold for﹩28, 000 (£22, 000).

    The handwritten letter was sent by Hemingway on 8 May to the fishing editor of the Miami Herald, laying out in great detail how the author and his friend Henry Strater battled to keep sharks away from the marlin after catching it off the Bahamian island of Bimini.

    Nate D Sanders, the auction(拍卖) company which sold the letter, said it documented for the first time in Hemingway's own words not only the size of the marlin, but also the attack by sharks, reflecting the plot of the novel.

    The company added that Hemingway's account of the marlin catch differed from other anecdotes of it, one of which described Hemingway using a machine gun on the sharks, which is said to have attracted more sharks rather than frightened them away.

    The Old Man and the Sea was also inspired by an anecdote told by Hemingway's Cuban friend Carlos Gutierrez. In 1936, Hemingway wrote in a magazine that Carlos had told him about an old fisherman who caught a great marlin alone.

    Three years later, Hemingway told his editor Max Perkins that he was planning a short story about the old commercial fisherman who fought the swordfish all alone in his sailing boat. Instead, he ended up writing For Whom the Bell Tolls, not returning to the story about the old fisherman until January 1951. It won him the Pulitzer in 1953, and was specifically cited when he was awarded the Nobel Prize in 1954.