Can eating a chocolate bar every day really prevent age-related memory loss? No. But a new research shows that large amounts of flavones, substances found in cocoa, tea and some kinds of vegetables, may improve age-related memory failure.

    Dr. Scott Small is a professor of neurology (神经病学) at Columbia University in new York City. He is the lead writer of a research paper describing the effects of cocoa flavones on brain activity. His study involved 37 volunteers aged between 50 and 69. Researchers gave them a high-level flavones drink made from cocoa beans or a low-level flavones drink. For a period of three months, some subjects got 900 milligrams of flavones a day. The others got 10 milligrams of flavones each day. Brain imaging and memory tests were given to each study subject before and after the study. Dr. Small says that the subjects who had the high-level flavones drink showed much improvement on memory tests.

    The researchers warn that more work is needed to be done because this study was performed only on a small group. Dr. Joann Manson is the lead researcher of a four-year study involving 18,000 adults. This study will use flavones capsules(胶囊). The study subjects will be divided into two groups and will take two pills per day. The capsules used will all look the same. But one group's capsules will contain flavones, while the other group will take capsules made of an inactive substance, or placebo

    Dr. Manson says it's not necessary for people to start eating more chocolate, because a person would have to eat a huge amount of chocolate to get the same level of flavones given to the rest subjects. He adds many manufacturers have planned to remove the flavones from their chocolate products. Similarly, Dr. Manson says a cocoa-based flavones extract(提取)may be developed in the future But he says that more studies are needed to see how much flavones is good for our health.

    From the very beginning of school we make books and reading a constant source of possible failure and public humiliation. When children are little we make them read aloud, before the teacher and other children, so that we can be sure they “know” all the words they are reading. This means that when they don't know a word, they are going to make a mistake, right in front of everyone. After having taught fifth-grade classes for four years, I decided to try at all costs to rid them of their fear and dislike of books, and to get them to read oftener and more adventurously.

    One day soon after school had started, I said to them, “Now I'm going to say something about reading that you have probably never heard a teacher say before. I would like you to read a lot of  books this year, but I want you to read them only for pleasure. I am not going to ask you questions to find out whether you understand the books or not. If you understand enough of a book to enjoy it and want to go on reading it, that's enough for me. Also I'm not going to ask you what words mean. “

    The children sat stunned and silent. Was this a teacher talking? One girl, who had just come to us from a school where she had had a very hard time, looked at me steadily for a long time after I had finished. Then, still looking at me, she said slowly and seriously, Mr Holt, do you really mean that?” I said just as seriously, “I mean every word of it.

    During the spring she really astonished me. One day, she was reading at her desk, From a glimpse of the illustrations I thought I knew what the book was. I said to myself, “It can't be,” and went to take a closer look. Sure enough, she was reading Moby Dick , in edition with woodcuts. I said, “Don't you find parts of it rather heavy going?” She answered, Oh, sure, but I just skip over those parts and go on to the next good part. “

    This is exactly what reading should be and in school so seldom is, an exciting, joyous adventure. Find something, dive into it, take the good parts, skip the bad parts, get what you can out of it, go on to something else. How different is our mean-spirited, picky insistence that every child get every last little scrap of “understanding” that can be dug out of a book.

    One day, I received a call from a colleague. He was about to give a student a zero for his answer to a physical problem， while the student claimed a perfect score. I was elected as their arbiter. I read the examination problem: “Show how it is possible to determine the height of a tall building with the aid of a barometer(气压计).” The student had answered: “Take the barometer to the top of the building，attach a long rope to it，lower it to the street， and then bring it up, measuring the length of the rope. The length of it is the height of the building. ”

    The student had really answered the question completely, but the answer didn't confirm his competence in physics. I suggested the student try again. I gave him six minutes to answer the question, warning that the answer should show some knowledge of physics. Five minutes later, he said he had many answers and clashed off one, which read： “Take the barometer to the top of the building and lean over the edge of the roof. Drop the barometer, timing its fall with a stopwatch. Then, use the physical formula (公式）to calculate the height of the building. ”

    At this point, my colleague had to accept it, and then the student made almost full marks. I couldn't help asking the student what the other answers were. He listed many others ，and then added “Probably the best is to take the barometer to the administrator and said to him，' Sir, here is a fine barometer. If you tell me the height of the building, I will give it to you.，”

    Then, I asked the student if he really did not know the conventional answer to this question. He admitted that he did, but said that he was fed up with high school and college instructors trying to teach him how to think.

    The name of the student was Bohr who later was famous all over the world. He won the Nobel Prize for Physics in 1922.

    In areas like the Central United States that get lots of tornadoes, there^'s a common piece of celestial （天上的）fortune-telling that green skies mean a tornado is on its way. Research has shown that it isn^'t quite as simple as that, but scientists have found that if you see a green sky, you should probably go inside. As far as most scientists can tell, the green skies around powerful thunderstorms are usually a combination of red sunsets and water droplets.

    Daytime skies are blue because blue shorter wavelengths of visible light tend to bounce off （反射）air molecules better than red longer wavelength light. So the blue light gets bounced all over the sky and looks like it's coming from everywhere. Meanwhile, around sunset sunlight travels through so much atmosphere that just about all the blue is bounced away from the horizon, leaving all those reds and oranges behind. The sunset might look exclusively （独有的）red and orange, but there's still some green and even blue light hidden in there, just far less than the other colors. But for us to notice the remaining green light, it needs to hit something that reflects green light much better than red. That's where water comes in.

    Big tall threatening storm clouds are made of water droplets, and even though water is best at reflecting blue light, it can still reflect green pretty well, much better than reds and oranges, so under just the right conditions, the water in and around a cloud can bounce the green light hidden in the sunset right into our eyes making the sky look green.

    Still, none of the conditions that can turn skies green are unique to the clouds that produce tornadoes. Sometimes they just lead to lots of rain, and maybe some hail. So if you see huge storm clouds rolling in and a green tint （色调）in the sky, it doesn't necessarily mean there^'s about to be a tornado, but it does mean you should probably head indoors.

    Stocky, slow-moving whale, rarely grows beyond 15 metres in length

    Flippers are a third of body length; variable dorsal fin size and shape; saw-toothed trailing edge on flukes, often raised when diving

    Bumpy tubercles on top of head

    Body colour is dark brown to black; often extensive white on flippers and underside of body and flukes; such patterns enable individual recognition

    Bushy blow, occasionally V-shaped

    270-400 olive baleen plates

    Humpback whales belong to the rorqual (groove-throated) family, which includes fin, sei, Bryde's, minke and blue whales. The big family migrate between winter tropical breeding areas (North West Shelf, Great Barrier Reef, New Caledonia, Vanuatu, Fiii, Tonga) and summer Antarctic feeding areas. Once common in New Zealand waters, humpbacks are now rarely seen and may migrate further offshore. Males compete for mates either by physical fight or by song. Females give birth to their young every two to three years; some non-breeding females probably remain in the southern waters during winter. Young humpback whales return to their area of birth but in later life some wander between breeding areas. Humpbacks eat small shrimps and other schooling prey, such as fish, forming small, cooperative groups of two to three individuals to feed.

    Similar species: Easily identifiable due to a 'hump' back when submerging, but at a distance may be confused with other species that raise their flukes when diving, such as sperm, right and blue whales.

    Protection status: Recovering well from past whaling and now numerous in some former migration and aggregation areas, rarely seen in others.

Something Fun

    A person is on trial for murder in a court room in Oklahoma. There is strong evidence indicating that he is guilty（有罪的）. However, the body is not found.

    In the defense's (辩护方) closing speech, the lawyer, knowing that his client (委托人) is guilty and that it looks like he'll probably be seriously punished, decided to play a clever trick.

    "Ladies and gentlemen of the jury (陪审团), I have a surprise for you all," the lawyer says as he looks at his watch. "Within one minute, the person assumed dead in this case will walk into this court room," he says and he looks towards the court-room door. The jury, somewhat surprised, looks at the door eagerly. A minute passes. Nothing happens.

    Finally the lawyer says, "Actually, I made up the previous statement. But you all waited with expectation. I, therefore, put it to you that there is a reasonable doubt in this case as to whether anyone was killed and insist that you pass a judgment of not guilty."

    The jury, clearly confused, back off to discuss.

    A very few minutes later, the jury returned and one of them pronounces a verdict (裁决) of guilty.

    "But how?" asks the lawyer in surprise  "You must have had some doubt; I saw all of you stare at the door."

    Answers the jury member, "Oh, we did look. But your client didn't."