You may have seen a talking parrot on a TV show, in a movie, or even in someone's home. The parrot has learned to copy sounds that people make. Birds are not the only animals that can copy the noises they hear. Dolphins, bats, and some apes also copy sounds. Now we can add elephants to this list of copycats.

    Dr. Joyce Poole is a zoologist. She studies the sounds of elephants. While she was in Kenya, she would hear strange noises made by Mlaika after sunset. Mlaika was a 10-year-old African elephant.

    Mlaika lived near a highway. Dr. Poole says, “I could not tell the difference between Mlaika's call and the distant truck noise.” She and other scientists studied Mlaika's sounds. It turned out that Mlaika was copying the sounds of the trucks driving by. Why would Mlaika copy trucks that she heard going by on the highway? Animals that are able to copy sounds may enjoy practicing new sounds. When they are kept outside of their natural environment, they may copy unusual sounds. That may be why an elephant would copy the sound of a truck.

    “Mlaika was not the only copycat elephant,” Dr. Poole says. Calimero is a 23-year-old male African elephant. He spent 18 years with two female Asian elephants. Asian elephants make chirping sounds (sounds made by birds) to talk with one another. African elephants usually do not make chirping sounds. But Calimero now does. He is copying his Asian elephant friends. Dr. Poole says that elephants need to form bonds with their family and friends. She says, “They make sounds to communicate with each other. When they are separated, they use sounds to keep in contact.”

    Parrots, dolphins, humans, and elephants show that being a copycat is one way that animals and people make new friends and keep old ones.

    Red meat, usually considered to be beef, pork, mutton and lamb products, have nutritional value, but eating red meat also raises some health concerns.

    Red meat is an excellent source of protein(蛋白质). It is also a key source of vitamin B12, which is only available in animal products and is key for both red blood cell and nerve health. Red meat is also a rich source of zine, selenium(硒) andiron. Zinc and selenium are good for our immune system (免疫系统). Iron helps transport oxygen in the blood, and low levels of iron can lead to feeling tired. Eating red meat, especially lean cuts(廋肉), with meals and snacks, may help people curb hunger between meals and help people with weight management.

    Health risks of red meat may include the risk of heart disease and cancer. It is usually best to avoid processed meats. These tend to contain lots of salt and nitrites(亚硝酸盐), which may damage our health. Choosing lean cuts and cooking meat correctly may reduce health risks. It is generally advised not to undercook or overcook red meat and to avoid grilling(烧烤).

    When it comes to red meat and health, another thing is whether the animals are grain or grass-fed. Grass-fed animals frequently have a better quality of life. Grass feeding can be more environmentally friendly as well.

    Many governments suggest the amount of red meat should be safely included in a healthy diet. The amount varies between nations, but several portions a week are usually acceptable. Those who choose to include eating red meat may wish to choose grass-fed animals and to cut off any fat before eating.

    Most dog owners feel that their dogs are their best friends. Almost everyone likes dogs because they try hard to please their owners. One of my favorite stories is about a dog who wanted the owner to please him. One of my friends has a large German shepherd(牧羊犬) named Jack. These dogs are often very intelligent (clever). Every Sunday afternoon, my friend takes Jack for a walk in the park. Jack likes these long walks very much.

    One Sunday afternoon, a young man came to visit my friend. He stayed a long time, and he talked and talked. Soon it was time for my friend to take Jack for his walk, but the visitor didn't leave. Jack became very worried about his walk in the park. He walked around the room several times and then sat down directly in front of the visitor and looked at him. But the visitor paid no attention. He continued talking. Finally, Jack couldn't stand(容忍) it any longer. He went out of the room and came back a few minutes later. He sat down again in front of the visitor, but this time he held the man's hat in his mouth.

    German shepherds aren't the only intelligent dogs. Another intelligent dog is a Seeing Eye dog. This is a special dog that helps blind people walk along the streets and do many other things. We call these dogs Seeing Eye dogs because they are the "eyes" of the blind people and they help them to "see". Seeing Eye dogs generally go to special schools for several years to learn to help blind people.

    Some students prefer a part-time job after class to earn some money and improve themselves. Here are some good companies:

    IN-N-Out Burger

    It is the best hamburger shop in the west of America. Regarded as one of the best employers, it offers flexible hours and the highest part-time salaries. Above all, the company treats its employees the way they would like to be treated: like family. However, there is no discount offered to its employees.

    Position: selling assistant (experience required)

    Website: in-n-out.cm

    Starbucks Coffee

    Starbucks has been at the forefront (前沿) of the United States' coffee revolution. Working hours are flexible. Fit twenty hours of work into your week. There is also a 30% discount and a free pound of coffee or box of tea every week.

    Position: assistant coffee taster (experience required)

    Website: starbucks.com

    Whole Foods Market

    Whole Foods Market is the world's largest natural and organic food selling company. With its focus on organic ingredients, Whole Foods Market is all about health. Working hours are free. Benefits include paid-time off and a 20% discount so you can eat like a king or at least like a top chef in training. There are also training courses on health and food every week.

    Position: secretary

    Website: wwholefoodsmarket.com.

    Lands' End

    Lands' End is a Wisconsin-based clothes store that focuses on casual comfort and warmth for the great outdoors. Employees (even part-time employees) have the chance to go to a company-owned entertainment center and get a 25% discount on theme parks and movies, and an invitation to the yearly company picnic. Besides, for part-time employees, they can come to work anytime they like as long as they work for 4 hours a day.

    Position: salesperson

    Website:landsend.com

    You may have heard that humans only use ten percent of their brain, and that if you could unlock the rest of your brainpower, you could do so much more. You could become a super genius, or acquire psychic powers like mind reading.

    This "ten-percent myth" has inspired many references in the cultural imagination. In the 2014 movie Lucy, for example, a woman develops godlike powers thanks to drugs that release the previously inaccessible 90 percent of her brain.

    Contrary to the ten-percent myth, however, scientists have shown that humans use their entire brain throughout each day.

    Over the years, brain scientists have shown that different parts of the brain are responsible for specific functions, whether it's recognizing colors or problem solving. Contrary to the ten-percent myth, scientists have proven that every part of the brain is integral for our daily functioning.

    Research has yet to find a brain area that is completely inactive. Even studies that measure activity at the level of single neurons(神经元) have not revealed any inactive areas of the brain.

    Many brain imaging studies that measure brain activity when a person is doing a specific task show how different parts of the brain work together. For example, while you are reading this text on your smartphone, some parts of your brain, including those responsible for vision and reading comprehension, will be more active.

    A more direct counter to the ten-percent myth lies in individuals who have suffered brain damage – like through a stroke(中风)– and what they can no longer do, or do as well, as a result of that damage. If the ten percent myth is true, then damage too many parts of our brain shouldn't affect your daily functioning. Studies have shown that damaging a very small part of the brain may have devastating consequences.

    If someone experiences damage to Broca's area(布罗卡氏区), for example, they can understand language but can't speak fluently.

    In one highly publicized case, a woman in Florida permanently lost her" capacity for thoughts, perceptions, memories, and emotions that are the very essence of being human" when a lack of oxygen destroyed half of her brain.

    Are you interested in travelling? Here are famous national parks where travellers mostly like to go in America.

    ⒈Great Smoky Mountains National Park

    Visitors: 11,388,893

    The name "Great Smoky Mountains" comes from the fog over this mountain range situated along the North Carolina-Tennessee border. Established in 1934, it is not just home to a diverse ecosystem of plants and animals, but also home to rich Appalachian cultures. Visitors there can see over 100 waterfalls, go boating on Fontana Lake and hike the Appalachian Trail. It's also an excellent vantage point to see the leaves change in the fall.

    ⒉Grand Canyon National Park

    Visitors: 6,254,238

    The Grand Canyon is the result of over 70 million years of geological events creating the Colorado Plateau, glaciers and valleys, while the Colorado River carved its way through the valleys. It is truly a natural splendor!

    When President Roosevelt first visited it in 1903, he said, "The Grand Canyon fills me with awe. It is beyond comparison – beyond description."16 years later, it was signed by President Woodrow Wilson, officially viewing the Grand Canyon a national park.

    ⒊Yosemite National Park

    Visitors: 4,336,890

    In addition to being a national park, Yosemite is designated as a World Heritage Site. Yosemite National Park is in Central California in the western Sierra Nevada. Though it covers around 1,168 square miles of area, visitors spend most of their time in the 5.9 square-mile area of the Yosemite Valley where there are some most famous sites like Yosemite Falls, and Cook's Meadow Loop.

    ⒋Zion National Park

    Visitors: 4,504,812

    Settled in Southwestern Utah is Zion National Park. It has some of the most unique landscapes packed with mountains, valleys, rivers, desert and forests.

    Zion National Park is also an important place to study ancient humans who made the area their home about 8,000 years ago. Some of the park's most notable attractions include Angel's Landing, Kolob Arch, the Narrows, etc.