Are we getting more stupid? According to Gerald Crabtree, a scientist at Stanford University in the US, we are.  You may not want to hear this, but Crabtree believes that human intelligence reached its peak more than 2,000 years ago and ever since then has been going downhill. “If an average Greek from 1,000 BC were transported to modern times, he or she would be one of the brightest among us,” Crabtree told The Guardian.

    At the heart of Crabtree's thinking is a simple idea. In the past, intelligence was critical for survival when our ancestors had to avoid dangerous animals and hunt for food. The difference of being smart or stupid is often life or death. However, after the spread of agriculture, when our ancestors began to live in dense ( 稠密的）farming communities, the need to keep their intelligence in peak condition gradually reduced. This is not hard to understand. Most of the time,pressure is what keeps us going – you need the pressure from your teachers to finish your homework; the pressure of looking pretty prompts(促使) you to lose weight when summer comes. And the same is also true of our intelligence – if we think less, we become less smart.

    These mutations(变) are harmful to our intelligence and they were all developed in the past 3,000 years. The other evidence that Crabtree holds is in our genes. He found that among the 2,000 to 5,000 genes that we have that determine human intelligence , there are two or more mutations in each of us. However, Crabtree's theory has been criticized by some who say that early humans may have better hunting and surviving abilities, but people today have developed a more diverse intelligence. For example, spearing a tiger doesn't necessarily require more brainpower than playing chess or writing a poem. Moreover, the power of modern education means a lot more people have the opportunity to learn nowadays. “You wouldn't get Stephen Hawking 2,000 years ago. He just wouldn't exist,” Thomas Hills of the University of Warwick, UK, told Live Science. “But now we have people of his intellectual capacity doing things and making insights(洞察力) that we would never have achieved in our environment of evolutionary adaptation.”

    Tonya, Elsa and Mark are students at LaGuardia High School in New York City. It's a school with regular academic (学术的) classes, but it also gives special attention to the performing arts. Tonya likes dancing, Elsa wants to be an artist and Mark is a singer.

    The students are all 15, and they're in 10th grade. They study subjects like English, math, social studies, science and PE. They also choose a foreign language: French, Italian, Spanish or Japanese. Students have many academic classes, but during the school day they also take classes in the arts, like theater, art, dance and music. Mark says, “I get the basic classes, but I also take a voice class and a music history class.”

    There is even more for LaGuardia students after school. There are more than 40 clubs for students. For example, there's a movie club, a music club and an environment club. “We have so many choices here,” says Tonya. “My favorite club is the camera club. I like taking photos. It's also a great way to meet people with common interests.”

    Students at LaGuardia can also do many sports. For example, they can play basketball, tennis, volleyball and soccer. Elsa is on the gymnastics team. She says, “I like being on a team. It makes me work hard and do my best.” Students practice after school. They compete against other high schools. Mark says, “At school, I study by myself. I'm a singer, and I do that alone, too. That's why I like playing on the basketball team. We work together and compete against other teams.”

    LaGuardia offers many great classes, clubs and sports for students. Students at LaGuardia get a good education and they also develop their own interests. Many LaGuardia students become dancers, singers and actors!

    Traditionally, robots have been hard, made of metal and other rigid material. But a team of scientists at Harvard University in the US has managed to build an entirely soft robot-one that draws inspiration from an octopus (章鱼).

    Described in science journal Nature, the "Octobot" could pave the way for more effective autonomous robots that could be used in search，rescue and exploration. "The Octobot is minimal system which may serve as a foundation for a new generation of completely soft, autonomous robots" the study's authors wrote.

Robots built for precise, repetitive movements in a controlled environment don't do so well on rough terrains (地形) or in unpredictable conditions. And they aren't especially safe around humans, because they're made out of hard and heavy parts that could be potentially dangerous to their users.

    So researchers have been working on building soft robots for decades. They're taken inspiration from nature, looking to animals from jellyfish to cockroaches, which are often made up of more flexible matter.

    But creating a completely soft robot remains a challenge. Even if engineers build a silicone (硅酮) body, it's still a grand challenge to construct flexible versions of essential parts, such as a source of power.

    "Although soft robotics is still in its early stage, it holds great promise for several applications, such as search-rescue operations and exploration," Barbara Mazzolai and Virgilio Mattoli of the Italian Institute of Technology' Center for Micro-BioRobotics, wrote in a comment. "Soft robots might also open up new approaches to improving wellness and quality of life."

    People can't see you when you're speaking on the phone, but they can hear you. So, the way you speak is especially important. In fact, researchers have calculated that 80% of communication over the phone is through your tone of voice; and only 20% is from the words you use. Here are our top tips on how to speak over the phone.

    ①Facial Expressions

    Your facial expression can influence your voice. For example, if you smile, your voice will sound warm and friendly, just the opposite, if you have an angry look on your face, it can make you sound unpleasant.

    ②Volume

    If you speak too loudly, you could sound angry. And if you speak too softly, it'll be difficult to hear you. So, speak loudly enough to be heard clearly, but not so loud that you're shouting.

    ③Pace

    The pace of your voice is how quickly you speak. And this can show how you feel. For example, an angry person might speak faster than normal. Or a downhearted person might speak very slowly. Try speaking a little more slowly than normal. This will make you sound confident, and it'll make it easier for the other person to understand you.

    ④Gestures

    Gesturing can influence the tone of your voice. When you gesture, you bring more air into the lungs, which can make your voice sound warmer. Gestures are also useful to help you stress the right words or even find the words you need. The best thing about gesturing during a phone call is that no one can see what you're doing, so you can gesture as wildly as you like!

    ⑤Movement

    If you're feeling nervous, stand up and move around. It will reduce the nervousness in your body and help your voice to sound more confident.

    ⑥Pauses (停顿)

    Using pauses every now and then can help you to slow down. This will make you sound more confident and in control. Also, if you pause after giving some new information, it'll give the other person time to understand it. At the same time, listen to how the other person uses pauses. They could tell you something about the speaker's feeling. For example, when a speaker is really angry, he might use pauses and says, "I…am…so…angry…"

    ①An increasing number of young people tend to rent clothes recently. Clothing rental is a hot new industry and retailers are entering this in hopes of attracting newly conscientious shoppers. This past summer alone, Urban Outfitters, Macy's, Bloomingdale's, American Eagle, and Banana Republic have all announced rental services—a sure sign of changing times.

    ②But is renting fashion actually more environmentally-friendly than buying it, and if so, how much more? Journalist and author Elizabeth Cline explored into this question and she concluded that it's not as sustainable as it seems.

    ③Take shipping, for example, which has to go two ways if an item is rented—receiving and returning. Cline writes that consumer transportation has the second largest carbon footprint(碳足迹)of our collective fashion habit after manufacturing.

    ④She writes, "An item ordered online and then returned can emit(排放)20 kilograms of carbon each way, and up to 50 kilograms for rush shipping. By comparison, the carbon impact of a pair of jeans purchased in physical stores and washed and worn at home is 33.4 kilograms, according to a 2015 study by Levi's."

    ⑤Then there's the burden of washing, which has to happen for every item when returned, regardless of whether or not it was worn. For most rental services, this usually means dry-cleaning, a high-impact and polluting process. 70 percent of US dry cleaners used perchloroethylene, a carcinogenic(致癌的)air pollutant, which can produce harmful waste and air pollution .

    ⑥Le Tote is the only service that uses 'wet cleaning' for 80 percent of its items and strives to avoid dry cleaning unless absolutely necessary.

    ⑦Lastly, Cline fears that rental services will increase our appetite for fast fashion, simply because it's so easily accessible. There's something called ‘share-washing' that makes people engage in more wasteful behaviors precisely because a product or service is shared and thus is perceived as more eco-friendly.

    ⑧Renting clothes is still preferable to buying them cheap and pitching them in the trash after a few wears, but we shouldn't let the availability of these services make us complacent(自鸣得意的). There's an even better step --and that's wearing what is already in the closet.