Do you often dream at night? How do you feel when you dream? Is it useful to our health? “Dreams may be more important than sleep, and we all need to dream,” some scientists say.

    Dreams take up about one quarter of our sleeping time. People have several dreams each night. Dreams are like short films. They are usually in colour. Some dreams are like old films. They come to us over and over again. That may be because the dreamer is worrying about something. Dreaming may be a way of trying to find an answer. Some people get new ideas about their work from dreams. They may have been thinking about their work all day. These thoughts can carry over into dreams.

    Sometimes we wake up with a good feeling from a dream. But often we can't remember the dream. Dreams can disappear quickly from memory.

    Too much dreaming can be harmful. The more we sleep, the longer we dream. The mind is at work when we dream. That is why we may have a long sleep and still wake up tired.

    We've all experienced the feeling that comes when your phone makes a sound to tell you that its battery level is low. It often comes at the worst times—when you're out on a trip and don't have a charger（充电器）, or when you're expecting an important phone call.

    Indeed, this feeling is so common that South Korean electronics manufacturer LG has given it a name: low battery anxiety（低电量焦虑）.

    According to a survey of 2,000 US adults conducted by the company last year, 90 percent of respondents said that they panic if their battery level reaches 20 percent or lower. And last month, UK telecommunications service provider found that around 15. 5 million Britons live in “constant fear” of their mobile phones running out of power, according to a survey by the company.

    “The problem is not about being unable to make calls, but is rooted in the fact that smartphones are now where we store digital memories,” noted the Daily Mail, However, battery worries don't just affect smartphone lovers. Many owners of electric vehicles also suffer from so-called “range anxiety”. This refers to the concern that the vehicle may not make it to its destination before the power runs out. Meanwhile, it isn't just low power that people worry about. A study carried out by South Korea's Sungkyunkwan University and China's City University of Hong Kong found that many of us also worry about not having constant access to our phone.

    This condition is known as homophobia, short for “ no mobile phone phobia（恐惧症）”. Symptoms include feeling uncomfortable when access to one's phone isn't possible, being unable to turn off your phone, and constantly topping up the battery to make sure it never dies.

    So, why do so many people treat their smartphone with such importance? The reason may be that they keep us connected to the people around us, and if we're unable to use our phone, we feel like we're cut off from our social life.

    With products with bigger batteries being released all the time-such as Xiaomi's Mi Max smartphone range or Tesla's Model S cars-battery anxiety may hopefully soon be a thing of the past.

    Animals can be reproduced by technology now; researchers can clone them. A clone is an exact copy of another animal or plant. Scientists have cloned a sheep which they have named Dolly. Researchers took genes from a ewe (母羊) and used them to create a copy (Dolly) of the ewe.

    Why are scientists doing this research? One reason is to get information about genes so they can improve our health. They also want to learn how better farm animals can be produced. Cloning is a controversial issue for people. Some people think it is good because this research can help us, but other people think cloning is unacceptable. Some people think it might be possible to save endangered animals by cloning them. Tigers, elephants, and other endangered animals might be saved in this way.

    In China, pandas are endangered because they are hunted and they are losing their habitat, so some Chinese scientists want to try to clone pandas to save them from extinction.

    I don't really like the idea of cloning animals, but I don't think I want panda to become extinct. If the best way to save them is to make cloned pandas, they must be cloned.

    I want to live with a lot of animals and nature. I don't want animals to die out, especially pandas. I think humans must think more about protecting animals and nature. Maybe cloning is the way to save all endangered animals.

    Vincent Van Gogh was the son of a pastor (牧师) in Holland. Around his early twenties he decided to become an artist. He felt that color was his main influence and he used it to express himself. The way he painted was very unusual during the late 1800s because he paid much attention to colorful abstract art. Van Gogh had many paintings that have changed the way we look at art. His paintings weren't popular during his lifetime because of an illness that was possibly a mental disorder. However, they are now considered to be the most popular forms of art in the world today. In what ways can we appreciate his paintings?

    Learn about the artistic style of expressionism. In Van Gogh's artwork, the style that he used was expressionism, which was the only one of this kind compared to other paintings.

    Look for key symbols that would help you understand his artwork better such as the background of the objects.

    Try to understand the artist's aims. You can do this by watching the use of colors, perspectives, and the subject. Knowing the artist's aims, you will be able to understand why he created the work.

    Take what you have learned from the artwork and put it in your feelings to see how it affects you and is related to you. This will allow you to make a connection with the artist.

    Parents who help their children with homework may actually be bringing down their school grades. Other forms of parental involvement, including volunteering at school and observing a child's class, also fail to help, according to the most recent study on the topic.

    The findings challenge a key principle of modern parenting(养育子女) where schools expect them to act as partners in their children's education. Previous generations concentrated on getting children to school on time, fed, dressed and ready to learn.

    Keith Robinson, the author of the study, said, "I really don't know if the public is ready for this but there are some ways parents can be involved in their kids' education that leads to declines in their academic performance. One of the things that were consistently negative was parents' help with homework." Robinson suggested that may be because parents themselves struggle to understand the tasks. "They may either not remember the material their kids are studying now, or in some cases never learn it themselves, but they're still offering advice."

    Robinson assessed parental involvement performance and found one of the most damaging things a parent could do was to punish their children for poor marks. In general, about 20% of parental involvement was positive, about 45% negative and the rest statistically insignificant.

    Common sense suggests it was a good thing for parents to get involved because "children with good academic success do have involved parents", admitted Robinson. But he argued that this did not prove parental involvement was the root cause of that success. "A big surprise was that Asian American parents whose kids are doing so well in school hardly involved. They took a more reasonable approach, conveying to their children how success at school could improve their lives."

Babies are surrounded by human language, always listening and processing. Eventually, they put sounds together to produce a "Daddy" or a "Mama". But what still confuses neuroscientists is exactly how the brain works to put it all together.

To figure it out, a team of researchers turned to a frequent stand-in (代替) for babies when it comes to language learning: the song-learning zebra finch. "We've known songbirds learn their song by first forming a memory of their father's song or another adult's song. Then they use that memory to guide their song learning," said Neuroscientist Todd Roberts. "It's been a long-term goal of the field to figure out how or where in the brain this memory is. This type of imitative learning that birds do is very similar to the type of learning that we engage in regularly—particularly when we're young, we use it to guide our speech learning."

Roberts and his team had a feeling that the interface (交叉区域) between sensory areas and motor areas in the brain was critical for this process, and they focused on a group of brain cells called the NIf.

"In order to prove that we could identify these circuits, we thought if we could implant a false memory." First, they used a virus to cause the neurons (神经元) in the birds' NIf to become sensitive to light. Then, using a tiny electrode as a flashlight, they activated (激活) the neurons. The length of each pulse of light corresponded with the amount of time the neurons would fire. And the birds' brains interpreted that time period as the length of each note.

Soon enough, the birds began to practice the notes they had learned, even though they never really heard the sounds. Amazingly, the birds produced them in the correct social situations. The researchers say this is the first time anybody has found exactly a part of the brain necessary for generating the sorts of memories needed to copy sounds.

"This line of research is going to help us identify where in the brain we encode memories of relevant social experiences that we use to guide learning. We know that there are several neurodevelopmental disorders in people that have really far-reaching effects on this type of learning."