There are two factors (因素) which decide an individual's intelligence (智商). The first is the sort of brain he is born with. Human brains differ greatly, some being more capable (有能力) than others. But no matter how good a brain he has to begin with, an individual (个体) will have a low order of intelligence unless he has opportunities to learn. So the second factor is what happens to the individual—the sort of environment in which he is brought up. If an individual has less chances environmentally, it is likely that his brain will fail to develop and he will never arrive at the level of intelligence of which he is capable.

    The importance of environment in deciding an individual's intelligence can be shown by the case history of the twins. When they were three months old, their parents died, and they were placed in different homes. Peter was brought up by parents of low intelligence in a separate community with poor educational opportunities. Mark was brought up in the home of well-to-do opportunity to be encouraged intellectually.

    This environmental difference continued until the twins were in their late teens, when they were given tests to measure their intelligence. Mark's IQ was 125, twenty-five points higher than the average and fully forty points higher than his twin brother. Given equal opportunities, the twins, having similar brains, would have tested at roughly the same level.

    It is easier to float in the ocean than it is to float in a swimming pool. Do you know why?

    Ocean water is full of salt— and salt water can hold up more weight than fresh water. See for yourself!

    You Will Need:

    3 cups of warm water

    Measuring cup (量杯)

    Wide-mouthed jar

    Salt

    Spoon

    Raw (生的)potato

    You Will Do:

    ⒈Pour 1.5 cups of warm water into the jar.

    ⒉Add 1/3 cup of salt.

    ⒊Stir(搅拌) until the salt is completely dissolved.

    ⒋Add another 1.5 cups of water. Pour it slowly over the back of the spoon into the jar so that the two liquids will not mix together.

    ⒌Gently place the potato into the jar. Do not drop it.

    What Will Happen:

    The potato will sink— but only halfway!

    Why?

    Salt water is heavier than fresh water, so it will stay on the bottom. The fresh water will remain on top.

    The potato is heavier than the fresh water, but it is lighter than the salt water. That is why the potato will sink halfway down.

    I'd like to share a story that happened when I was four. I remember it clearly. Our loving family dog was nearing the end of his life. My father picked him up and put him in a little bed we had made for him. Our dog, my companion, whom we had cared for, bit (咬) my father when he tried to help him. How could he? Why? I couldn't understand it. I didn't like him anymore.

    I hadn't thought about that story for a long time but something that happened last week brought it back to me. I went to speak with a friend. When I knocked on the door, I met an angry look and a few harsh (尖刻的) words. When the door was slammed (砰地关上) in my face, I stood there shocked, and in a rush, I was reminded of my dog bit my father 20 years ago or so. What brought that story back was that same feeling of betrayal (背叛).

    Both stories taught me something the next day. You see, when I got up in the morning and was told my dog had died, it became clear to me that he must have been in great pain. For him to have bitten a family member, he could not have been himself. Much the same for the other story when I learned that my friend's wife had just left him.

    We are all beings of our environments, our opinions and feelings. And all of those things can cause you to say and do things that can't be understood by those who are not in the same situation with you.

    If you meet someone either behaving out of character or acting in a way that doesn't seem to fit the situation, put out your hand and be patient when you think it is least possible for him to do so. You may turn around a story that has a sad ending simply by your actions.

    A good disguise keeps you hidden, right? Well, sometimes the best disguise is actually the most dazzling because research reveals that flashy metallic iridescence(金属彩虹色) can visually puzzle predators, which allows colorful prey to survive another day. Those surprising results appear in the journal Scientific Reports.

    Shining iridescent color, which changes depending on the angle from which it's viewed, is favored by everything from birds to beetles and blossoms to butterflies.

    "And in our research group we are of course interested in why this vivid metallic color is so widespread in nature." Karin Kjernsmo of the University of Bristol adds that in some cases the showy splashes of light are a sexual strategy. " Here I would like to point out that in some species, particularly those that display strong sexual dimorphism(雌雄两性), such as birds of paradise or some butterflies or fishes, the occurrence of iridescence is most likely driven by sexual selection. For example, in many of these cases it is the males that have these vivid iridescent colors and they use them in mate choice or they use them as a signal to attract mates."  But iridescence also shows up in situations where reproduction is not an issue. " So what we are studying now is whether natural selection imposed by predation(捕食行为) could explain the occurrence of iridescence in prey animals."

    The idea that eye­catching colors could be used as a cover­up isn't a new one." The father of camouflage theory, Abbott Thayer, really believed that iridescence should be categorized as a camouflage strategy. And he wrote in his famous lifework Concealing­Coloration in the Animal Kingdom, already in 1909, that 'brilliantly changeable or metallic colors are among the strongest factors in an animal's concealment'. And this sounds like a completely unreasonable thing to say, because how can colors that are both brilliant and changeable contribute to animal's concealment？"

    "In a similar way, we were asking whether iridescence, due to its changeability, could work as a form of camouflage by preventing shape recognition." Kjernsmo and her colleagues trained bumblebees to associate a particular shape—a circle or an oval—with a sugar reward. And they found that the bees, when given a choice, would preferentially visit the shape they knew to be sweet. But when the shapes were iridescent, the bees had trouble telling them apart. "It seemed that the strikingly iridescent surfaces on our targets visually broke up the otherwise recognizable shape of the targets, which made them hard to distinguish." As for making use of this method for hiding in plain sight, "Any practical applications is of course directly linked to any industry that has an interest in camouflage, that is how to conceal objects or make them more difficult to recognize." The researchers are currently conducting experiments with birds, which often prey on iridescent insects to see if it helps to have a bird's­eye view.

    You've probably heard such reports. The number of college students majoring in the humanities (人文学科) is decreasing quickly. The news has caused a flood of high-minded essays criticizing the development as a symbol of American decline.

    The bright side is this: The destruction of the humanities is, finally, coming to an end. No more will literature, as part of an academic curriculum, put out the light of literature. No longer will the reading of, say, "King Lear" or D.H. Lawrence's "Women in Love" result in the annoying stuff of multiple-choice quizzes, exam essays and homework assignments.

    The discouraging fact is that for every college professor who made Shakespeare or Lawrence come alive for the lucky few, there were countless others who made the reading of literary masterpieces seem like two hours in the dentist's chair.

    The remarkably insignificant fact that, a half-century ago, 14% of the undergraduate population majored in the humanities (mostly in literature, but also in art, philosophy, history, classics and religion) as opposed to 7% today has given rise to serious reflections on the nature and purpose of an education in the liberal arts.

    Such reflections always come to the same conclusion: We are told that the lack of a formal education, mostly in literature, leads to numerous harmful personal conditions, such as the inability to think critically, to write clearly, to be curious about other people and places, to engage with great literature after graduation, to recognize truth, beauty and goodness.

    Literature changed my life long before I began to study it in college. Books took me far from myself into experiences that had nothing to do with my life, yet spoke to my life. But once in the college classroom, this precious, alternate life inside me got thrown back into that dimension of my existence that bored me. Homer, Chekhov and Yeats were reduced to right and wrong answers, clear-cut themes and clever interpretations. If there is anything to worry about, it should be the disappearance of what used to be an important part of every high-school education: the literature survey course, where books were not academically taught but thoroughly introduced—an experience unaffected by stupid commentary and useless testing.

    The literary classics are places of quiet, useless stillness in a world that despises (鄙视) any activity that is not profitable or productive. Literature is too sacred to be taught. It needs only to be read.

    Soon, if all goes well and literature at last disappears from the undergraduate curriculum—my fingers are crossed—increasing numbers of people will be able to say that reading the literary masterworks of the past outside the college classroom, simply in the course of living, was, in fact, their college classroom.

A healthy lifestyle includes many choices. Among them, choosing a balanced diet or healthy eating plan is of the greatest importance. But how do you choose a healthy eating plan? Let's begin by explaining what a healthy eating plan is.

A healthy eating plan that helps you manage your weight includes different kinds of foods you may not have considered. If "healthy eating" makes you think about the foods you can't have, try refocusing on all the new foods you can eat.

Fresh, Frozen, or Canned Fruits -- don't think about just apples or bananas. All fresh, frozen, or canned fruits are great choices. Be sure to try some fruits from other countries, too. How about a mango, a juicy pineapple or kiwi fruit? What you should pay attention to about canned fruits is that they may contain added sugars. You'd better choose canned fruits packed in water or in their own juice.

Fresh, Frozen, or Canned Vegetables – try something new. Don't eat the same kinds of vegetables all the time. You can try to eat different kinds of vegetables, which is important for a good diet. When trying canned vegetables, look for vegetables without added salt or butter. You can go to the produce department(果蔬部) and try a new vegetable each week.

Calcium(钙)-rich foods -- you may firstly think of a glass of low-fat or fat-free milk when someone says "Eat more dairy products " But what about low-fat and fat-free yogurts without added sugars? There is a wide variety of flavors and they can be a great dessert instead of those with a sweet tooth.

What's more, you don't need to give up your favorite comfort food. You can enjoy your favorite foods even if they are high in calories, fat or added sugars. The key is eating them only once in a while, and balancing them out with healthier foods and more physical activity.

The point is that you can figure out how to include almost any food in your healthy eating plan in a way that still helps you lose weight or maintain a healthy weight.