题目内容
When he was ordered from above to expel two______comrades-they insisted on challenging the
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Many nutritionists, having known for decades that saturated fat, found in
abundance in red meat and dairy products, raises blood cholesterol levels that
are in turn associated with a high risk of coronary heart disease, have fallen
Line victim to the temptation of simplifying dietary recommendations to facilitate
(5) public nutrition education. After decades of promoting the consumption of all
complex carbohydrates and eschewing all fats and oils, much of this theory has
been discredited.
Controlled feeding studies in which the participants eat carefully prescribed
diets for several weeks substantiated that saturated fat increases cholesterol
(10) levels, and that polyunsaturated fat-found in vegetable oils and fish-reduces
cholesterol. Dietary advice should therefore emphasize the replacement of
saturated fat with polyunsaturated fat, not total fat reduction. The subsequent
doubling of polyunsaturated fat consumption that this advice might inspire could
potentially contribute to a halving of coronary heart disease rates.
(15) Indeed, the argument that fat in general is to be avoided has been hastily
extrapolated from observations that affluent Western countries have both high intakes
of fat and high rates of coronary heart disease. This correlation is limited to saturated
fat, however, for societies in which people eat relatively large portions of
monounsaturated and polyunsaturated fat (whose health benefits are nearly identical)
(20) tend to have lower rates of heart disease. On the Greek island of Crete, for
instance, where the traditional diet contained much olive oil, a rich source of
monounsaturated fat, and fish, a source of polyunsaturated fat, fat constituted
40 percent of the calories in this diet, but the rate of heart disease was lower
than the rate for those who followed the traditional diets of Japan, where fat
(25) composes only 8 to 10 percent of the calories. Furthermore, international
comparisons of overall fat intake can be misleading: many negative influences
on health, such as smoking, physical inactivity and high amounts of body fat,
are also correlated with Western affluence. Many nutritionists decided it would
be too difficult to educate the public about these subtleties, instead advocating a
(30) clear, simple message that fat was insalubrious.
The wisdom of this practice has further come into question as researchers
discover that the two main cholesterol-carrying chemicals, low-density
lipoprotein (LDL), and high-density lipoprotein (HDL), have very different
effects on the risk of coronary heart disease, such that increasing the ratio of
(35) LDL to HDL in the blood raises the risk, whereas decreasing the ratio has the
opposite effect. Unfortunately, certain controlled feeding studies have shown
that when a person replaces calories from saturated fat with an equal amount of
calories from carbohydrate-rich polyunsaturated fats, not only the levels of LDL
and total cholesterol diminish, but also the level of HDL, and thus in only a
(40) limited reduction in risk accrues from shifting to a polyunsaturated fat diet.
With which of the following statements concerning the tradit
Part A
Directions: Read the following four texts. Answer the questions below each text by choosing A, B, C or D . Mark your answers on ANSWER SHEET 1.
We sometimes think humans are uniquely vulnerable to anxiety, but stress seems to affect the immune defenses of lower animals too. In one experiment, for example, behavioral immunologist (免疫学家)Mark Laudenslager, at the University of Denver, gave mild electric shocks to 24 rats. Half the animals could switch off the current by turning a wheel in their enclosure, while the other half could not. The rats in the two groups were paired so that each time one rat turned the wheel it protected both itself and its helpless partner from the shock. Laudenslager found that the immune response was depressed below normal in the helpless rats but not in those that could turn off the electricity. What he has demonstrated, he believes, is that lack of control over an event, not the experience itself, is what weakens the immune system.
Other researchers agree. Jay Weiss, a psychologist at Duke University School of Medicine, has shown that animals who are allowed to control unpleasant stimuli don't develop sleep disturbances or changes in brain chemistry typical of stressed rats. But if the animals are confronted with situations they have no control over, they later behave passively when faced with experiences they can control. Such findings reinforce psychologists' suspicions that the experience or perception of helplessness is one of the most harmful factors in depression.
One of the most startling examples of how the mind can alter the immune response was discovered by chance. In 1975 psychologist Robert Ader at the University of Rochester School of Medicine conditioned (使形成条件反射) mice to avoid saccharin (糖精) by simultaneously feeding them the sweetener and injecting them with a drug that while suppressing their immune systems caused stomach upsets. Associating the saccharin with the stomach pains, the mice quickly learned to avoid the sweetener. In order to extinguish this dislike for the sweetener, Ader re-exposed the animals to saccharin, this time without the drug, and was astonished to find that those mice that had received the highest amounts of sweetener during their earlier conditioning died. He could only speculate that he had so successfully conditioned the rats that saccharin alone now served to weaken their immune systems enough to kill them.
Laudenslager's experiment showed that the immune system of those rats who could turn off the electricity ________.
What is suggested if you want to keep your friends？
听力原文： The first step in writing is to get over the guilt of not writing. You don' t "owe” anybody a letter. Letters are a gift. The burning shame you feel when you see unanswered mail makes it harder to pick up a pen and makes for a cheerless letter when you finally do. Skip sentences like "I feel bad about not writing, but I' ve been so busy, "etc. A few letters are obligatory, and they are "Thanks for the wonderful gift "and "You are welcome your friends to stay with me. "and not many more than that. Write those promptly if you want to keep your friends. Don' t worry about others, except love letters, of course. When your true love writes "Dear light of my life; joy of my beart, "some response is called for.
Keep your writing stuff and in one place where you can sit down for a few minutes. For ex ample, keep envelopes, stamps, an address book, everything in a drawer so you can write fast when the mood strikes you.
Sit down for a few minutes with the blank sheet in front of you, and meditate on the person you will write to. Let your friend come to mind until you can almost see her or him in the room with you. Remember the last time you saw each other and how your friend looked and what you said and what perhaps was unsaid between you. And when your friend becomes real to you, start to write.
Write the salutation - Dear You - and take a deep breath and plunge in. A simple declarative sentence will do, followed by another and another and another. Tell us what you' re doing and tell it like you were talking to us. Don't think about grammar, don't think about style, don't try to write dramatically, just give us your news. Where did you go, who did you see, what did they say, what do you think.
How to get over the first step to write a letter？
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