There was once a captain who loved money so much that he cheated his sailors at the end of every voyage and took their wages (工资).

    On the last day of one voyage, the ship was in a small port. It was winter time, and the sea was very cold, so the captain said to his sailors, “If one of you stays in the water during the whole night, I will give him my ship. But if he comes out before the sun appears, I shall get his wages.”

    The sailors (船员) had heard about the captain's cheating, so they didn't trust him. But then one of them, who thought that he was cleverer than the captain, said that he would do it. He got into the water, and, though it was very cold, he stayed in it. When it was nearly morning, some fishermen lit a fire on the shore about half a mile away.

    “You are cheating,” the captain said to the sailor. “The fire's warming you.”

    “But it's half a mile away!” said the sailor.

    “A fire's fire,” answered the captain. “I have won.”

    The sailor came out of the water, and said, “Perhaps you think that you are clever because you have won my wages, but you can't cook a chicken.”

    “I can,” answered the captain.

    “If you cook this chicken,” said the sailor, “I shall work for you without wages for seven years, but if you can't, you will give me your ship.”

The captain agreed, took the chicken and said, “Where's the fire?”

    “There it is,” answered the sailor. “On the shore.”

    “But it's half a mile away,” said the captain angrily.

    “‘A fire's fire,' you said,” answered the sailor. “If it is enough to warm me in the water, it is enough to cook your chicken.”

    Petra and Wadi Rum, Jordan

    When it comes to the world's wonderful desert scenery, Jordan's Petra and Wadi Rum has it. Also known as the Valley of the Moon, this place is one of the best due to its amazing desert canyons (峡谷) and rock walls. Participants love exploring its Burdah and Um Fruth, walking to the impressive ancient city.

Kilimanjaro, Tanzania

    The Rongai Route is the best route if the participants of the walking tour want a quiet climb. The Kili Trail permits travelers to witness the region's wilderness, virgin forests, and rare animals. This route, according to many, is the easiest way to reach the top where the breath-taking 360-dcgree sights of natural wonders await.

    Quebec, Canada

    This special environment made up of both the natural and cultural treasures, where fresh water becomes one with the tides (潮汐) of the sea, makes Quebec one of the interesting walking tour destinations in the world. Here is a track that heads to the Saguenay Fjord National Park which is included in the UNESCO World Heritage Site. Adding to the beauty of Quebec are its sparkling waterfalls, inviting lakes, and rare animals.

    Great Smoky Mountain, US

    This region has been named as the ancestral home of the Cherokee Indians, where rich natural wonders combined with interesting history are the major happenings. The rich natural reserve is evident and enjoyed by walking tour participants. What also makes this destination a popular choice is its reputation as the biggest wilderness on the eastern part of the United States.

    October might seem to be pumpkin month in the U.S. The holiday of Halloween (万圣节) comes on October 31. Americans around the country are already using social media to show off their pumpkin growing and carving skills.

    Pumpkins are round, orange fruits related to squashes (南瓜小果) and gourds (葫芦). People use their flesh and seeds for food, but they are also popular decorations in the fall.

    Two big pumpkins recently made headlines in the U.S. A farmer in the northeastern state of Rhode Island broke the record for the largest pumpkin ever grown in North America. Richard Wallace's pumpkin weighed 1,026 kilograms. It broke his son's record from 2015. Ron Wallace's pumpkin only weighed 1,011 kilograms last year. A schoolteacher in the northwestern state of Washington brought her large pumpkin to an event in California. Her pumpkin was the champion, weighing 866 kilograms. It turns out that Cindy Tobeck's pumpkin grew from one of the seeds from Ron Wallace's pumpkin from 2015.

    While those pumpkins are large, they are still not the largest in the world. According to the website BigPumpkins.com, Richard Wallace's pumpkin is only the second-heaviest pumpkin of the year. A man in Belgium produced a pumpkin that weighed almost 1,200 kilograms. Smithsonian magazine wrote a story about people who try to grow large pumpkins. In 35 years, the size of record pumpkins has grown from about 225 kilograms to over 1,000 kilograms. Pumpkin farmers trying to grow record fruits are taking the seeds of champion pumpkins from one year and breeding them with other large pumpkins.

    But people are not just growing pumpkins. They are carving them, too. One Twitter user from Britain recently posted a photo of a pumpkin designed to look like U.S. presidential candidate Donald Trump. No word of a Hillary Clinton pumpkin design. But one pumpkin farmer in California allows visitors to shoot small pumpkins out of a cannon（大炮）. The targets? Large paper cut-outs of both Trump and Clinton.

    Most groups of plants and animals are richer in species and more plentiful near the equator. In the ocean, that holds true for cold-blooded predators(掠食者). But warm-blooded predators are more diverse toward the poles and noticeably missing from several warm hot spots. Why?

    John Grady, an ecologist, and his team considered the possibility—warm-blooded animals need a lot to fuel their metabolism(新陈代谢). Perhaps colder waters are just richer in small fish? But they found that at higher, colder places, there isn't actually much more food around. It's more that warm-blooded animals are eating a much bigger share of it than their cold-blooded competitors.

    The real explanation is simple. An animal's speed, swiftness, and intelligence depend on its metabolism, which in turn depends on its temperature. Since birds and mammals can keep heating their bodies in icy conditions, they remain fast and attentive. By contrast, the fish they hunt become slower and duller. At some tipping point of temperature, seals, dolphins, and penguins start out swimming their prey(猎物). They become more likely to come upon targets and outpace the cold-blooded predators of their own.

    In Grady's words, "Warm-bodied predators are favoured where preys are slow, stupid and cold." That's why sharks and other predatory fish dominate near the equator, but colder waters are the kingdom of whales and seals. By keeping food to themselves in the poles, these creatures can then specialize on specific types of prey, which makes them more likely to split into separate species. The killer whales of the North Pacific, for example, include mammal-eating transients and fish-eating, year-round residents.

    But the world is changing. It's likely that the surface of the oceans will warm by 2 to 3℃ within this century. Grady's team estimates that every time the ocean's surface warms by 1℃, populations of sea mammals will fall by 12%, and populations of seals and sea lions will fall by 24%.

    But "predictions are hard," Donna Hauser from the University of Alaska Fairbanks notes. "Polar bears are losers of a warming world, but some populations are still doing well. Some groups of whales have changed the timing of their migrations; others are hunting in deeper, colder waters. These changes might make sea mammals more adaptable to changing climates. Maybe they just need to find the places where fish remain slow, stupid and cold."

Benefits and Problems of Genetic Engineering

    Plant breeding is the science of changing the characteristics of plants in order to produce desired ones. Genes in a plant are what determine what type of characteristics it will have. Plant breeders try to create a specific outcome of plants and potentially new plant varieties by changing the genes of the plants through breeding, which is making new plants from parents of different varieties or species.

    Actually, plant breeding has been practiced for thousands of years, since near the beginning of human civilization. It is practiced worldwide by individuals such as gardeners and farmers and by professional plant breeders employed by organizations such as government institutions, universities, crop-specific industry associations or research centers. They have crossbred plants to create the new types of plants that are, for example, bigger, stronger, or more attractive.

    Crossbreeding can take such a long time, however, and it is inaccurate. Now, we can change exact sections of Deoxyribonucleic acid (DNA), so the process is more accurate and faster. But people all over the world are arguing about its benefits and disadvantages. Some people use the technology to produce desired characteristics of plants and animals. Other people are concerned that the genetically engineered plants may harm the environment and worried that they may be dangerous for people to eat.

    There are many reasons for changing plants in this way. International development agencies believe that breeding new crops is important for ensuring food security by developing new varieties that are higher yielding(高产的), disease resistant, drought tolerant or regionally adapted to different environments and growing conditions. For example, some genetically engineered plants can live through frost or draught. As a result, famers can make more profit because fewer plants will die.

    Some genetically engineered plants are more nutritious. They have less fat, taste better or stay fresher than non-genetically engineered plants. This will allow people to buy better-quality fruit and vegetables.

    Some genetically engineered plants can resist natural pests such as viruses or insects. This reduces the amount of chemical needed to kill pests, which is helpful to the environment.

    However, genetically engineered plants can cause unexpected problems. Genetically engineered plants that resist pests may pass on that characteristic to a wild relative. This may cause the wild plant to spread fast, because pests are not naturally killing it.

    Genetically engineered plants can also harm animals. A type of corn has been developed which kills a species of insect that destroys it. The pollen (花粉) from this corn, however, can also kill monarch butterflies—the most beautiful of all butterflies, which do not harm the corn.

    To ensure the most adapted varieties are identified, advocates of organic breeding now promote the use of direct selection for many desired characteristics.

    Genetic engineering is a very new science and we have a lot to learn about the good it can do and the damage it can cause. The main concern is that not enough tests are being done to ensure it is safe.