Language learning begins with listening. Children are greatly different in the amount of listening they do before they start speaking, and later starters are often long listeners. Most children will “obey” spoken instructions some time before they can speak, though the word “obey” is hardly accurate as a description of the eager and delighted cooperation usually shown by the child. Before they can speak, many children will also ask questions by gesture and by making questioning noises.

    Any attempt to study the development from the noises babies make to their first spoken words leads to considerable difficulties. It is agreed that they enjoy making noises, and that during the first few months one or two noises sort themselves as particularly expressive as delight, pain, friendliness, and so on. But since these can't be said to show the baby's intention to communicate, they can hardly be regarded as early forms of language. It is agreed, too, that from about three months they play with sounds for enjoyment, and that by six months they are able to add new words to their store. This self-imitation leads on to deliberate imitation of sounds made or words spoken to them by other people. The problem then arises as to the point at which one can say that these imitations can be considered as speech.

    It is a problem we need to get our teeth into. The meaning of a word depends on what a particular person means by it in a particular situation and it is clear that what a child means by a word will change as he gains more experience of the world. Thus the use at seven months of “mama” as a greeting for his mother cannot be dismissed as a meaningless sound simply because he also uses it at other times for his father, his dog, or anything else he likes. Playful and meaningless imitation of what other people say continues after the child has begun to speak for himself. I doubt, however, whether anything is gained when parents take advantage of this ability in an attempt to teach new sounds.

    The TED speaker series features “ideas worth spreading.” With over 1,400 to choose from, we've selected a few that are perfect for students.

    Larry Smith: Why You Will Fail to Have a Great Career

    We humans have an excellent ability to make excuses for ourselves. Larry Smith, a professor of economics at the University of Waterloo in Canada, tells us why most of us will fail to have a great career. But there is a way out— if you try to pursue your passion.  

    Andy Puddicombe: All It takes Is 10 Mindful Minutes

    Between dance team, volunteering and—oh, right—lectures, your life's crazy factor is about to go way up. In this entertaining and informative talk, mindfulness expert Andy Puddicombe teaches us how to be “healthier, more mindful and less distracted” by taking just 10 minutes out of the day to be more present.

    Shane Koyczan: To This DAY for the Bullied and Beautiful

    This talk is sure to stay with you. Shane Koyczan's “To this DAY” is an affecting spoken-word poem about bullying and being different that gained over 10 million views on YouTube. In this talk, Koyczan gives a live reading of the poem, along with some stories about his background.

    Susan Cain: The power of Introverts (性格内向者)

    Does a cup of tea and a good book sound like a perfect Friday night? In this personal talk, Susan Cain argues that introverts have important talents and abilities. Our culture may value being social and outgoing, but the world needs all kinds.

    To err is human. To blame the other guy is even more human.

    Common sense is not all that common.

    Why tell the truth when you can come up with a good excuse?

    These three popular misquotes (戏谑的引语) are meant to be jokes, and yet they tell us a lot about human nature. To err, or to make mistakes, is indeed a part of being human, but it seems that most people don't want to accept the responsibility for having made a mistake. They naturally look for someone else who could be responsible for the problem. Perhaps it is the natural thing to do. The original quote about human nature went like this: “To err is human, to forgive, divine (神圣的).” This saying mirrors an ideal: people should be forgiving of others' mistakes. Instead, we tend to do the opposite —— find someone else to pass the blame on to. However, taking responsibility for something that went wrong is a mark of great maturity.

    Common sense is what we call clear thought. Having common sense means having a good general plan that will make things work well, and it also means staying with the plan. Common sense tells you that you take an umbrella out into a rainstorm, but you leave the umbrella home when you hear a weather forecast for sunshine. Common sense does not seem to be common for large organizations, because there are so many things going on that one person cannot be in charge of everything. People say that in a large company, “the right hand does not know what the left hand is doing.”

    And what is wrong with a society that thinks that making up a good excuse is like creating a work of art? One of the common problems with making excuses is that people, especially young people, get the idea that it's okay not to be totally honest all the time. There is a corollary (直接推论) to that: if a good excuse is “good” even if it isn't honest, then where is the place of the truth?

    Young people's mental health is of increasing interest and concern to researchers, policymakers, and families alike－but can treating teenagers' mental health problems also improve the wellbeing of their parents? New research suggests that it can. The study, conducted by Kelsey Howard, a doctoral candidate at Northwestern University, found that regardless of which treatment teenagers were using for their depression, the mental health of their parents improved too.

    Older findings say that there is a link between mothers' depression and major depression in their teenagers, although it seems not to be biological. However, the latest research suggests that the relationship between parents' and their children's mental health might work in the other direction too.

    While Howard's research hasn't evidenced a clear reason for this trend, she told The Atlantic: “If the family members interact with (交往) each other well, the kid will be more pleasant to be around and make less negative statements, which will affect how other family members think.”

    Tom Madders, director of campaigns at YoungMinds, told HuffPost UK that for parents, watching their children go through mental health problems can be difficult, especially if they feel responsible. Madders also noted that parents often make big lifestyle changes, say, giving up their jobs, to support their children with depression, particularly in cases where their children have to leave school because of their mental health problems. However, Madders thought this can only make things worse. “Parents' sacrifice adds pressure to the delicate shoulder owners,” he said.

    The process of waiting to get treatment can also be an added stressor: “Every day we get calls to our helpline from parents whose children have been waiting months for an initial assessment, or left on long waiting lists for treatment that they need … that's why it's important that the Government commits to long-term extra investment in children's mental health services.”

    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.

How to Celebrate Earth Day

Are you looking for ways to celebrate Earth Day on April 22? You've come to the right place. If you're ready to learn more about joining the global celebration, making real change, and doing your part to save our planet, read on!

Walk or ride your bike. {#blank#}1{#/blank#} Even one day can make a difference, but if you can commit(承诺)to walking or biking more often in the future, that's even better! If your daily commute(通勤) is too far for walking or biking, try public transportation like buses or trains.

Plant a tree. This simple act will benefit the environment for decades. Planting a tree only takes a few minutes, but it can make a huge impact. {#blank#}2{#/blank#} They help to save energy, clean pollution, and provide homes for many birds, insects, and other local wildlife.

Attend a local Earth Day event. {#blank#}3{#/blank#} If your community doesn't have one planned, consider starting one yourself. It's the perfect day to get together for a fun and educational celebration of the earth.

Visit a local farmer's market. Eating locally grow n food is much better for the environment. For example, locally-grown food doesn't have to be transported long distances to end up on grocery store shelves. {#blank#}4{#/blank#}.

Commit to one green act per day. You can keep reducing your carbon(碳) footprint once Earth Day is over. {#blank#}5{#/blank#} While small changes at the individual level may not seem like a big deal, they add up over time and can have a major impact. Moving forward, make it your goal to do one small thing every day to support the environment.

A.Earth Day can be every day!

B.Trees are extremely important.

C.Trees need extra care to grow well.

D.Get out there and appreciate our beautiful world.

E.Going car-free for the day will reduce harmful gases.

F.See if your community is holding an environmental fair.

G.You'll also be giving back to your community by supporting local farmers.