If you have ever been left wondering why your emails are riddled(充斥着) with grammatical errors, or why you can never quite find the right phrase, it may be because you are typing with both hands.

    Our vocabulary becomes richer and our writing style becomes more fluent when we type using just one hand, scientists have found. "Typing can be too fluent or too fast, and it can actually weaken the writing process," said Srdan Medimorec, the lead author of the study conducted at the department of psychology at the University of Waterloo, Canada. "It seems that what we write is a product of the interaction(互动) between our thoughts and the tools we use to express them."

    Using text-analysis software, researchers asked 103 university students to write essays under different conditions, using one hand to type and using both hands to type. The software was used to analyze(分析) elements of the essays, such as range of vocabulary, sentence complexity and the cohesion(衔接) of the writing.

    Researchers found that participants' vocabulary became more advanced when they typed with one hand rather than two. The research team said that by slowing our writing down, typing one-handed allows more time for an internal (内在的) word search, resulting in a larger variety of words.

    In contrast, fast typists might just write the first word that comes to mind. However, it is important not to slow typing down too much. Those who typed essays one-handed in the current study slowed down to about the speed of handwriting.

    This is the first study to show that changing people's typing can make their writing get better. The researchers suggested that the speed of writing could affect writing quality regardless of the tools used, whether they are computers, or pen and paper, although further research would be required to prove that idea.

    Scientists from the University of East Anglia have identified four new man-made gases that are contributing to the damage to the ozone(臭氧) layer. Two of the gases are accumulating at a rate that is causing concern among researchers.

    Worries over the growing ozone hole have seen the production of chlorofluorocarbon (CFC) gases restricted since the mid 1980s. But the precise origin of these new, similar substances remains a mystery.

    Lying in the atmosphere, the ozone layer plays a critical role in blocking harmful UV rays, which cause cancers in humans and reproductive problems in animals.

    Scientists from the British Antarctic Survey were the first to discover a huge “hole” in the ozone over Antarctica in 1985. The evidence quickly pointed to CFC gases, which were invented in the 1920s, and were widely used in refrigeration. Extraordinarily, global action was rapidly agreed to deal with CFCs and the Montreal Protocol to limit these substances came into being in 1987. A total global ban on production came into force in 2010.

    Now, the newly discovered four new gases can destroy ozone and are getting into the atmosphere from as yet unidentified sources. Three of the gases are CFCs and one is a hydrochlorofluorocarbon (HCFC), which can also damage ozone.

    The research has shown that four gases were not around in the atmosphere at all until the 1960s, which suggests they are man-made. The scientists discovered the gases by analyzing polar snow pack. Air from this snow is a natural archive of what was in the atmosphere up to 100 years ago. There searchers also looked at modern air samples, collected at remote Cape Grim in Tasmania.

    They estimate that about 74,000 tonnes of these gases have been released into the atmosphere. Two of the gases are accumulating at significant rates. However, they don't know where the new gases are being released from and this should be investigated. Possible sources include chemicals for insecticide (杀虫剂)production and solvents (溶液) for cleaning electronic components. The three CFCs are being destroyed very slowly in :the atmosphere—so even if emissions (散发)were to stop immediately, they will still be around for many decades to come.

    Of the four species identified, CFC-113a seems the most worrying as there is a very small but growing emission source somewhere, maybe from agricultural insecticides. We should find it and take it out of production.

    When we think someone is smart，we say they have a big brain．But are there any facts to prove that statement？

    Yes! In a new study done by Michael McDaniel, a psychologist at Virginia Commonwealth University，bigger does mean smarter. "For all ages and sex groups，"he says，"it is now very clear that intelligence has something to do with brain volume（容量）．"

    McDaniel reached his conclusion after measuring the size and volume of 26 brains with the help of some instruments. He then used standard IQ tests to measure the intelligence of the owners of these brains.

    But do IQ tests really reveal intelligence？McDaniel believes that they do，and here are other studies to backup that point of view．One study last year found that IQ is related to the amount and distribution（分布） of gray matter in the brain．The study showed that the amount of gray matter in certain places was strongly related to high IQ．The distribution of gray matter in the brain，which is different for different people，could explain why one person with a high IQ is good at math but poor at spelling，while someone else with the same IQ has just the opposite ability．

    Yet another recent study found that women have more gray matter（compared with white matter） than men！However，the study also showed that in the areas of the brain specifically（特别地） related to intelligence，men had much more gray matter，which is needed for some tasks，such as doing a math problem. Women, on the other hand, had more white matter, which is necessary for collecting information．And the point is that intelligence can be influenced in different ways．

    "On average，"McDaniel says，"smarter people learn more quickly，make fewer mistakes，and are more productive．"He believes in the use of IQ tests to examine those who want to find a job. So, be well, do good work, and…exercise that brain!

    "I feel unlikable, lonely and hopeless," said Lisa, a bright teenager from a loving home. "It seems that nobody wants to become my friend. What's wrong with me?"

    Like Lisa, many of us experience loneliness. The truth is that all people, no matter what their age or character — even the most outgoing, wealthy and popular — experience loneliness at least sometimes. It's healthy and natural to want to be around people who care. After all, we've all heard "No man is an island." That's true. We all need others in our lives.

    Solomon, the wisest man who ever lived, explains that if we want friends, we must be friendly and reach out to others. But it has risk. Because we are often afraid of rejection (拒绝), many of us are unwilling to reach out to others. We take a safer way and wait for others to make friends with us. But if we want friends, we've got to get beyond this.

If making friends is your goal as well, you need to consider taking some measures (措施).

    Be willing to take the initiative (主动权). If you see someone whom you would like to know, don't wait for her to make the first move. Get close to her and begin a conversation. Let her know in a non­aggressive (无攻击性的) way that you are interested in being friends with her.

    Reach out to those who are lonely. When you see someone at school sitting alone, go over and talk to her. And don't let popularity decide whom you reach out to. You'll often be surprised at the beautiful qualities behind a shy appearance.

    Ask questions. Start your first conversation by asking this possible friend what she likes to do or asking about her family. Be sure to ask questions that cannot be replied with "yes" or "no". For example, don't ask "Do you have a dog?" Instead, say "So, tell me about your pets." Avoiding asking "yes" or "no" questions makes your possible friend not end your communication with a one­word answer.

    There is a very long list of rules for the New York City subway. Don't put your feet on a seat, don't carry open cups of coffee or soda, don't take more than one seat... Those are just a few of the rules. There are hundreds more.

    With so many rules, why is it still unpleasant to ride the subway?

    Some people think that the problem is that no one enforces the rules. Other passengers sometimes try to enforce rules. But you can't rely on them because New Yorkers have unwritten rules against talking to strangers and making eye contact with strangers. How can you tell someone to take her shopping bags off the seat and throw away her Coke without talking to her or looking at her? It is difficult.

    There are other New Yorkers who think that the subway is unpleasant because there are not enough rules. One rider wrote a letter to The New York Times a couple of weeks ago suggesting a few more subway rules. Here are some of the rules that she would like to see:

    —Don't lean on the poles. You prevent other people from holding on. They can fall down.

    —Talk quietly. The trains are already too noisy.

    —Give your seat to elderly passengers or to parents with small children.

    If those unwritten rules of etiquette are written down, will the rude people be more likely to follow them? It doesn't make sense to make more rules that no one will enforce.

    The real problem is that we are forgetting how to be nice to each other. It is embarrassing that we need a rule to tell us to give our seat to elderly passengers. Nobody should need to be reminded to do that.

    I say we stop talking about the rules and try to remember our manners. Let's be nice to each other not because a police officer might tell us to get off the train, but because it is the right thing to do. Then New York City would be more civilized —both above ground and below.

If you've ever seen a sparrow steal your dog food or a crow open a garbage bag, you get a sense of that some birds have learned to take advantage of new feeding opportunities—a clear sign of their intelligence. Scientists have long wondered why certain species of birds are more innovative than others, and whether these capacities stem from larger brains or from a greater number of neurons（神经元）in specific areas of the brain.

It turns out that it's a bit of both, according to a recent study by an international team that included members from McGill University published in Nature Ecology and Evolution.

The researchers used a new technique to estimate the number of neurons in a specific part of the brain called the pallium in 111 bird species. The pallium in birds is equal to the human cerebral cortex（大脑皮层）, which is involved in memory, learning, reasoning, and problem-solving, among other things. When these estimates about neuron numbers in the pallium were combined with information about over 4,000 feeding innovations, the team found that the species with the higher numbers of neurons in the pallium were also likely to be the most innovative.

"The amount of time chicks spend in the nest as their brains develop might also play a crucial role in the evolution of intelligence," says McGill University Emeritus Professor Louis Lefebvre who spent more than 20 years gathering examples of feeding innovations. "Larger species of crows and parrots, which are known for their intelligence, spend longer in the nest, which allows more time for the brain to grow and accumulate pallial neurons."

The results of the study help to deal with previously opposed views of the evolution and significance of brain size and show how a life-history perspective helps to understand the evolution of cognition.