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    Nowadays, the Internet is usually one of the first places a lonely heart turns to as the following story shows.    

    A 63-year-old retired woman in Zhengzhou, made headlines two days after she posted an advertisement on her Wechat(微信) page, in which she said she wanted to find a young female companion for a trip to Sanya, China's Southern Hainan island, a local newspaper Dahe Daily reported. In the advertisement, the Chinese dama (Chinese term for middle-aged and elderly women) surnamed (a person's last name) Li said she is in good health, and she was particularly looking forward to a sea trip this winter.

    "I have a daughter who works in Canada, and I don't want to disturb her. My husband rarely has time to travel with me. But I'm afraid of traveling alone, so I am looking for a sweet, happy young woman, aged between 19 and 25 to travel with me. Hope she could chat with me, take photos with me."

    At the end of the advertisement, Dama Li showed her sincerity by saying she would be responsible for all the costs of the trip, including accommodation(膳宿) and air tickets, plus an iPhone 7 as a gift. Dama Li told Dahe Daily that she did not expect her advertisement to receive so much attention. "My phone keeps buzzing all the time. "However, some people question the truth of Li's advertisement. They say it might be organized by travel agencies aiming to promote(促进，推销) Sanya tourism, or even served as a promotional advertisement for real estate（房地产） on the island. Li denied those doubts and said all she wants is just to find a sweet "daughter".

    But Li's advertisement for a daughter has also received as many online mockeries(嘲笑) as positive feedback.

    Recently a new study has been carried out. It shows students who write notes by hand during lectures perform better on exams than those who use laptops.

    Students are increasingly using laptops for note-taking because of speed and legibility (清晰度). But the research has found laptop users are less able to remember and apply the concepts they have been taught.

    Researchers performed experiments that aimed to find out whether using a laptop increased the tendency to make notes “mindlessly” by taking down word for word what the professors said.

    In the first experiment, students were given either a laptop or pen and paper. They listened to the same lectures and were told to use their usual note-taking skills. Thirty minutes after the talk, they were examined on their ability to remember facts and on how well they understood concepts.

    The researchers found that laptop users took twice as many notes as those who wrote by hand. However, the typists performed worse at remembering and applying the concepts. Both groups scored similarly when it came to memorizing facts.

    The researchers' report said, “While more notes are beneficial, if the notes are taken mindlessly, as is more likely the case on a laptop, the benefit disappears.”

    In another experiment aimed at testing long-term memory, students took notes as before but were tested a week after the lecture. This time, the students who wrote notes by hand performed significantly better on the exam.

    These two experiments suggest that handwritten notes are not only better for immediate learning and understanding, but that they also lead to superior revision in the future.

    Humans' invention of zero was vital for modern mathematics and science, but we're not the only species to consider “nothing” a number. Parrots and monkeys understand the concept of zero, and now bees have joined the club, too.

    Honey bees are known to have some numerical skills such as the ability to count to four, which may come in handy when keeping track of landmarks in their environment. To see whether these abilities extended to understanding zero, researchers trained 10 bees to identify the smaller of two numbers. Across a series of trials, they showed the insects two different pictures displaying a few black shapes on a white background. If the bees flew to the picture with the smaller number of shapes, they were given delicious sugar water, but if they flew toward the larger number, they were punished with bitter-tasting food.

    Once the bees had learned to consistently make the correct choice, the researchers gave them a new choice: a white background containing no shapes at all. Even though the bees had never seen an empty picture before, 64% of the time they chose it rather than a picture containing two or three shapes, the authors report today in Science. This suggests that the insects understood that “zero” is less than two or three. And they weren't just going for the empty picture because it was new and interesting. Another group of bees trained to always choose the larger number tended to pick the nonzero image in this test.

    In further experiments, the researchers showed that bees' understanding of zero was even more complex: for example, they were able to distinguish between one and zero-a challenge even for some other members of the zero club. Advanced numerical abilities like this could give animals an evolutionary advantage, helping them keep track of predators（捕食者）and food sources. And if an insect can display such a thorough grasp of the number zero, write the researchers, then this ability may be more common in the animal kingdom than we think.

    Dreaming of summer picnics filled with family and fun? We've come up with 4 of the top picnic areas across the US.

    Cumberland Islands, Georgia

    Just a few hours south of Savannah, this national seashore is a picnic paradise. It's an unspoiled place in the Deep South with over 50 miles of hiking trails (小径). Covered in Spanish moss, the trails are lined with trees and since it's still a rural area, the stars line up for a spectacular show at night and create the perfect evening starlit picnic opportunity.

    Grant Park, Chicago

    If you are looking for delicious food in Chicago, go for a taste of a 20-day, lake-front, foodie festival that happens in October each year. Grab a spot near the fountain to enjoy your picnic, appreciate the city scenery and lake views and relax with family and friends. If you are there on July 4^th, be sure to plan the day to include the fireworks display at the Navy Pier.

    Cranberry Islands, Maine

    Here, you'll enjoy natural picnics with island views. The islands are a delightful group of islands about 20 minutes offshore from Acadia National Park. You can visit the islands by private boat or ferry (渡船) service. Bring a picnic basket along for the ride as it's a romantic picnic area to take your special someone or go for a family outing to visit the islands.

    Big Sur, California

    The Point Lobos State Reserve is a small gem. Besides the coastal wildlife there are rare plant communities, and unique geological formations. It's good to have a picnic there. We recommend bringing a telescope, because much of the wildlife can be seen only at a distance.

    More than 40 percent of the species that help with pollination (植物传粉) are under threat due to the polluted environment. So some researchers have been searching for ways to protect the bees and other crucial pollinators while some engineers have thought perhaps an army of robotic pollinators could keep humans well-supplied in these foods. A team of researchers has recently designed a small drone capable of pollinating flowers. They tested their device on the large, pink flowers of lilies. And it worked.

    Exciting as this success was, it is only the first step. The team has yet to figure out how to apply the concept on the massive scale. Could a fleet of robo-pollinators replace the bees?

    “Although the answer isn't a straightforward no, it would be a challenging leap to go from this one little drone pollinating one large flower to an army of drones spreading across fields of crops,” says Scott Swinton, an agricultural economist at Michigan State University.

    “The successful pollination was fascinating,” Scott Swinton says, “but the device itself might damage the flowers. I wonder how you make sure you're not doing more harm than good to flowers when you have a drone.”

    “Furthermore,” he points out, “a lily is a particularly easy flower for a drone to pollinate. To make this more broadly applicable for smaller and more complex flower structures, the drones would need to be particularly agile.”

    Still, Joshua Campbell, an expert at the University of Florida, says “Pollination systems are extremely complex and will always require insects. There is no substitute for bees.”

    “As for the technology itself, it is a promising new development in existing drone technology,” he added. Yet he still sees some hurdles ahead before drones can be applied on a large scale.

    Global warming is the process of earth's atmosphere heating up. Over the last 100 years, the average temperature of earth's atmosphere has gone up 1 Fahrenheit. The weather has not changed exactly the same way in every area of the planet. But scientists think that the rise in average temperature is already affecting the earth, s climate.

    Many scientists now believe that global warming is caused by cutting down trees, producing more trash, and polluting the environment are some of the reasons that the temperature has gone up. Many scientists believe that the biggest causes of global warming are new human technologies that release greenhouse gases into the atmosphere.

    The greenhouse effect is not new. Certain gases in the atmosphere, like carbon dioxide, nitrous oxide and methane, prevent heat energy from escaping back into space. In the past, the climate didn't change much because nature produced just the right amount of greenhouse gases to deal with it.

    Today, most scientists are pretty sure that the rising temperature can't be blamed on nature. Ever since the industrial revolution in the 1700s, humans have relied on machines for daily life. And many of those machines give off a lot of greenhouse gases. An increase in the release of greenhouse gases from human activities is throwing nature off balance.

    The climate is a very complicated thing, but many scientists agree that the rising atmospheric temperature has already damaged the environment. Sheets of ice, called glaciers, are melting in Antarctica and other parts of the globe. As glaciers break off and melt into the oceans, they are adding warm water to the oceans and causing the sea level to rise.

    Over the past last 100 years, the sea level has risen 6-8 inches around the world. That means land along the coasts is beginning to disappear under water. Bigger and warmer oceans are also adding to other weather problems caused by pollution in the atmosphere. Some places have received more rain, others have had bigger storms and a few areas in the world have experienced unusual droughts.