While dog keepers realize their dogs can read their moods accurately, scientists have always been a little doubtful. Now thanks to some researchers at the University of Veterinary Medicine in Vienna, Austria, we finally have some convincing evidence.

    For their study, biologist Corson Miller and his team exposed eleven selected dogs to digital images of women that were either angry or happy. Half the dogs were rewarded for touching the screen when shown a happy face, while the other half got their treat for selecting those that appeared angry.

    Interestingly, the dogs were not provided with the entire face. Some dogs were shown only upper halves while the others observed lower halves. That's because the scientists believe humans show their emotions on their entire face.

    After some training like how to recognize small differences like the wrinkles between the eyes or the changes in their shape that accompany the happy or angry expressions, the dogs were mostly able to identify the correct expression not only on a familiar face but on a strange face. The researchers concluded the dogs were smart enough to read human emotions.

    They also found those being trained to read angry expressions took a longer time to learn. They guess it may be because dogs find angry faces disgusting, causing them to withdraw quickly. However, once the smart dogs realized they were getting rewarded, the trepidation seemed to disappear. In fact, the dogs had such a good time playing the computer "game" that scientists had a hard time keeping them away from the touch screens after the study was completed.

    The researchers also noticed only dogs with a male owner had a harder time understanding the expressions correctly. Since the touchscreen models were all females, this confirmed what has been observed in previous studies—dogs are more efficient at reading facial expressions of people that are the same gender as their owner.

    A small group of people around the world have started implanting(移植) microchips to link the body and the computer.

    Mr. Donelson and three friends, who had driven 100 miles from their homes in Loockport, New York, to have the implants put in by Dr. Jesse Villemaire, whom they had persuaded to do the work, are part of a small group, about 30 people around the world, who have independently put in microchips into their bodies, according to Web-based reports.

    At a shop William Donelson was having a four-millimeter-wide needle put into his left hand. “I'm set,”he said with a deep breath. He watched as the needle pierced(刺穿) the fleshy webbing between his thumb and a microchip was set under his skin. At last he would be able to do what he had long imagined: strengthen his body's powers through technology.

    By putting the chip inside—a radio frequency identification device (RFID)—Mr. Donelson would have at his fingertips the same magic that makes safety gates open with a knock of a card, and bridge and tunnel traffic flow smoothly with an E-Zpass. With a wave of his hand he plans to connect with his computer, open doors and unlock his car.

    Implanting the chip was relatively simple task but very meaningful to Mr. Doneselson, a 21-year-old computer networking student so interested in the link between technology and the body that he has data-input jacks(数据输入插空) inside his body. They might lead to an imagined future when people can be connected directly into computers. His new chip is enclosed in a glass container no bigger than a piece of rice and has a small memory where he has stored the words “Technology”.

    Some doctors have done the piercing in people's homes, and others have implanted chips in their offices after patients signed forms showing the fact that long-term studies have not been done on their safety. Piercers treat the implants much like any other medical operation steps, instructing people to keep the site dry, and advising them that swelling and redness should last a week.

根据短文内容，选择最佳答案，并将选定答案的字母标号填在题前括号内。

    She was returning from teaching out in a small community. It was a black, moonless night, and a heavy snow was falling.

    She thought back to the time when she had first started teaching out in small communities. During those days she had always picked up hitchhikers (搭便车者), until the day her sister told her that one of her friends had been shot in the head by a hitchhiker, all because she had stopped out of kindness to help him during a storm.

    Her family didn't stop worrying about her safety over the hitchhikers until the family heard the promise: “No more hitchhikers!” The snow that night was making her think back to this.

    Then she saw a man waving. She slowed down for him, but as he ran toward the car in the dark, she shook with fear. Yet she thought that if he was truly in need, she couldn't leave him here in this storm.

    The stranger explained that his car was dead, and she told him to get in. They drove for an hour into the next city and she took him to a convenience store. She waited until he had made a call. When he reported back to her that a family member would soon come to pick him up, she wished him well and then left.

    Tears fell on her cheeks as she drove away. It felt as though she had been holding her breath for an hour.

    “I hope they'll understand why I had to break my promise,” she thought.

    Every man wants his son to be somewhat of a clone（克隆）, not in features but in footsteps. As he grows you also age, and your ambitions become more unachievable. You begin to realize that your boy, in your footsteps, could probably achieve what you hoped for. But footsteps can be muddied and they can go off in different directions.

    My son Jody has hated school since day one in kindergarten. Science projects waited until the last moment. Book reports weren't written until the final threat.

    I've been a newspaperman all my adult life. My daughter is a university graduate working toward her master's degree in English. But Jody? When he entered the tenth grade he became a "vo-tech" student (技校学生). They're called "motorheads" by the rest of the student body.

    When a secretary in my office first called him "motorhead", I was shocked. "Hey, he's a good kid," I wanted to say. "And smart, really."

    I learned later that motorheads are, indeed, different. They usually have dirty hands and wear dirty work clothes. And they don't often make school honor rolls (光荣榜).

    But being the parent of a motorhead is itself an experience in education. We who labor in clean shirts in offices don't have the abilities that motorheads have. I began to learn this when I had my car crashed. The cost to repair it was estimated at $800. "Hey, I can fix it," said Jody. I doubted it, but let him go ahead, for I had nothing to lose.

    My son, with other motorheads, fixed the car. They got parts (零件）from a junkyard, and ability from vo-tech classes. The cost was $25 instead of $800.

    Since that first repair job, a broken air-conditioner, a non-functioning washer and a non-toasting toaster have been fixed. Neighbors and co-workers trust their car repairs to him.

    These kids are happiest when doing repairs. They joke and laugh and are living in their own relaxed world. And their minds are bright despite their dirty hands and clothes.

    I have learned a lot from my motorhead: publishers need printers, engineers need mechanics, and architects need builders. Most important, I have learned that fathers don't need clones in footsteps or anywhere else.

    My son may never make the school honor roll. But he made mine.

    People typically wash their hands seven times a day in the United States, but they do it at a far higher temperature than is necessary to kill germs, a new study says. The energy waste is equivalent to the fuel use of a small country. Amanda R. Carrico, a research assistant professor at the Vanderbilt Institute for Energy and Environment in Tennessee, told National Geographic that hand washing is often “a case where people act in ways that they think are in their best interest, but they in fact have inaccurate beliefs or outdated perceptions.”

    Carrico said, “It's certainly true that heat kills bacteria, but if you were going to use hot water to kill them it would have to be a way too hot for you to tolerate.”

Carrico said that after a review of the scientific literature, her team found “no evidence that using hot water that a person could stand would have any benefit in killing bacteria.” Even water as cold as 40°F (4.4℃) appeared to reduce bacteria as well as hotter water, if hands were scrubbed, rinsed(冲洗)and dried properly.

    Using hot water to wash hands is therefore unnecessary, as well as wasteful, Carrico said, particularly when it comes to the environment. According to her research, people use warm or hot water 64 percent of the time when they wash their hands. Using that number, Carrico's team calculated a significant impact on the planet.

    “Although the choice of water temperature during a single hand wash may appear unimportant, when multiplied by the nearly 800 billion hand washes performed by Americans each year, this practice results in more than 6 million metric tons of CO2 equivalent emissions annually,” she said.

    The researchers published their results in the July 2013 issue of International Journal of Consumer Studies. They recommended washing with water that is at a “comfortable” temperature, which they noted may be warmer in cold months and cooler in hot ones.

Western monarch butterflies(帝王蝶)spend their winters on the central California coast. A few months later, they produce young in the Central Valley and as far north and east as Idaho. But where they go in between remains an open question to biologists. Therefore, a group of biologists call on anyone who spots a monarch north of Santa Barbara this spring to get a quick shot(镜头)and email them the photo with a date and a location.

"Something's going on in early spring," said Cheryl Schultz, a professor at Washington State University Vancouver. "Winter survival isn't the problem in the short term, but they don't know whether the monarchs are not making it producing places, not finding plants to feed themselves along the way," she said.

The Western monarch population stood in the millions in the 1980s. In 2017, an annual count found 200,000 butterflies. In 2018, the number fell to about 30, 000-a figure that held steady last year. The monarchs' decline is part of a large trend among dozens of butterfly species in the West. What exactly caused the decline? Biologists attach it to a variety of reasons. Many chemicals are sprayed on the milkweed(乳草)monarchs will feed on. Climate change also plays a role in challenges facing monarchs. Yet, they're not nearly as threatening as those leading to loss of their living room. Farms used to have rough borders that were grounds for the plants monarchs love and live in. However, newly applied practices pushed crops to the edge of fields.

"Butterflies often have good and bad years. We do think there's potential to turn the situation around." Dr. Schultz said. And she said she saw two reasons for that. First, the population decline seen in 2017 ~ 2018 wasn't repeated last year. And second, she's seen butterfly populations recover before.