Science is an enterprise concerned with gaining information about causality, or the relationship between cause and effect. A simple example of a cause is the movement of a paddle as it strikes a ping-pong ball; the effect is the movement of the ball through the air. In psychology and other sciences, the word "cause" is often replaced by the term "independent variable". This term implies that the experimenter is often "free" to vary the independent variable as he or she desires (for example, the experimenter can control the speed of the paddle as it strikes the ball). The term "dependent variable" replaces the word "effect", and this term is used because the effect depends on some characteristic of the independent variable (the flight of the ball depends on the speed of the paddle). The conventions of science demand that both the independent and dependent variables be observable events, as is the case in the ping-pong example. In the case of biorhythm theory, the independent variable is the number of days that have elapsed between a person’’s date of birth and some test day. The dependent variable is the person’’s level of performance on some specified task on the test day. Notice that although the experimenter is not free to choose a birthday for a given individual, persons with different dates of birth can be tested on the same day, or a single subject can be tested on several different days. 　　In order to predict the relationship between independent and dependent variables, many scientific theories make use of what are called intervening variables. Intervening variables are purely theoretical concepts that cannot be observed directly. To predict the flight of a ping-pong ball, Newtonian physics relies on a number of intervening variables, including force, mass, air resistance, and gravity. You can probably anticipate that the intervening variables of biorhythm theory are the three bodily cycles with their specified time periods. It should be emphasized that not all psychological theories include intervening variables, and some psychologists object to their use precisely because they are not directly observable. 　　The final major component of a scientific theory is its syntax, or the rules and definitions that state how the independent and dependent variables are to be measured, and that specify the relationships among independent variables, intervening variables, and dependent variables. It is the syntax of biorhythm theory that describes how to use a person’’s birthday to calculate the current status of the three cycles. The syntax also relates the cycles to the dependent variable, performance, by stating that positive cycles should cause high levels of performance whereas low or critical cycles should cause low performance levels. To summarize, the components of a scientific theory can be divided into four major categories: independent variables, dependent variables, intervening variables, and syntax. Based on the text, causality may have the meaning that

A:cause and effect can be independent of each other. B:there is hardly anything that happens without a cause. C:dependent and independent variables affect each other. D:cause and effect may vary respectively in most events.

Diet is second only to tobacco as a leading (1) of cancer and, along with alcohol, is responsible for nearly one third of cases of the disease (2) developed countries, a leading researcher said on Tuesday.
Dr. Tim Key, of the University of Oxford, told a cancer conference that scientists are still discovering how certain foods contribute to (3) , but they know that diet, alcohol and obesity (4) a major role.
"Five percent of cancers could be avoided (5) nobody was obese, " he said.
While tobacco is linked to about 30 (6) of cancer cases, diet is involved in an estimated 25 percent and alcohol (7) about six percent.
Obesity raises the (8) of breast, womb, bowel and kidney cancer, while alcohol is known to cause cancers of the mouth, throat and liver. Its dangerous impact is (9) when combined with smoking.
Key told the meeting of the charity Cancer Research UK (10) other elements of diet linked to cancer are (11) unknown but scientists are hoping that the EPIC study, which is comparing the diets of 500,000 people in 10 countries and their risk of cancer, will provide some (12) .
Early results of the study have revealed that Norway, Sweden and Denmark have the (13) consumption of fruit and vegetables among European countries while Italy and Spain have the highest. Eating at (14) five portions of fruit and vegetables a day is recommended to reduce the risk of cancer.
Key, principal scientist on the EPIC study, said it is looking at dietary links to some of the most common cancers (15) colorectal, breast and prostate.

1（）

A:course B:cause C:court D:reason

Diet, Alcohol Linked to Nearly One Third of Cancers
Diet is second only to tobacco as a leading (1) of cancer and，along with alcohol，is responsible for nearly one third of cases of the disease (2) developed countries, a leading researcher said on Tuesday.
Dr. Tim Key, of the University of Oxford, told a cancer conference that scientists are still discovering how certain foods contribute to (3) , but they know that diet, alcohol and obesity (4) a major role.
"Five percent of cancers could be avoided (5) nobody was obese," he said.
While tobacco is linked to about 30 (6) of cancer cases, diet is involved in all estimated 25 percent and alcohol (7) about six percent.
Obesity raises the (8) of breast, womb, bowel and kidney cancer, while alcohol is known to cause cancers of the mouth, throat and liver. Its dangerous impact is (9) when combined with smoking.
Key told the meeting of the charity Cancer Research UK (10) other elements of diet linked to cancer are (11) unknown but scientists are hoping that the EPIC study, which is comparing the diets of 500, 000 people in 10 countries and their risk of cancer, will provide some (12)
Early results of the study have revealed that Norway, Sweden and Denmark have the (13) consumption of fruit and vegetables among European countries while Italy and Spain have the highest. Eating at (14) five portions of fruit and vegetables a day is recommended to reduce the risk of cancer.
Key, principal scientist on the EPIC study, said it is looking at dietary links to some of the most common cancers (15) colorectal, breast and prostate.

51（）

A:course B:cause C:court D:reason

? ?下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。请仔细阅读短文，并根据短文回答其后面的问题，从4个选项中选择1个最佳答案。
{{B}}第一篇{{/B}}

? ?Another common type of reasoning is the search for causes and results. We want to know whether cigarettes really do cause lung cancer, what causes malnutrition, the decay of cities, or the decay of teeth. We are equally interested in effects: what is the effect of sulphur of lead in the atmosphere, of oil spills and raw sewage in rivers and the sea, of staying up late on the night before an examination?
? ?Causal reasoning may go from cause to effect or from effect to cause. Either way, we reason from what we know to what we want to find out, Sometimes we reason from an effect to a cause and then on to another effect. Thus, if we reason that because the lights have gone out, the refrigerator won’t work, we first relate the effect (lights out) to the cause (power off) and then relate that cause to another effect (refrigerator not working). This kind of reasoning is calls, for short, effect to effect. It is quite common to reason through an extensive chain of causal relations. When the lights go out we might reason in the following causal chain: lights out—power off—refrigerator not working—temperature will rise—milk will sour. In other words, we diagnose a succession of effects from the power failure, each becoming the cause of the next.
? ?Causes are classified as necessary, sufficient, or contributory. A necessary cause is one which must be present for the effect to occur, as combustion is necessary to drive a gasoline engine. A sufficient cause is one which can produce an effect unaided, though there may be more than one sufficient cause: a dead battery is enough to keep a car from starting, but faulty spark plugs or an empty gas tank will have the same effect. A contributory cause is one which helps to produce an effect but cannot do so by itself, as running through a red light may. help cause an accident, though other factors--pedestrians or other cars in the intersection—must also be present.
? ?In establishing or refuting (驳倒) a causal relation it is usually necessary to show the process by which the alleged (所谓的) cause produces the effect. Such an explanation is called a causal process.

What the author discussed in the previous section is most probably about ______.

A:relationships between cause and results B:classification of reasoning C:some other common types of reasoning D:some special type of reasoning

? ?下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。请仔细阅读短文，并根据短文回答其后面的问题，从4个选项中选择1个最佳答案。
{{B}}第一篇{{/B}}

? ?Another common type of reasoning is the search for causes and results. We want to know whether cigarettes really do cause lung cancer, what causes malnutrition, the decay of cities, or the decay of teeth. We are equally interested in effects: what is the effect of sulphur of lead in the atmosphere, of oil spills and raw sewage in rivers and the sea, of staying up late on the night before an examination?
? ?Causal reasoning may go from cause to effect or from effect to cause. Either way, we reason from what we know to what we want to find out, Sometimes we reason from an effect to a cause and then on to another effect. Thus, if we reason that because the lights have gone out, the refrigerator won’t work, we first relate the effect (lights out) to the cause (power off) and then relate that cause to another effect (refrigerator not working). This kind of reasoning is calls, for short, effect to effect. It is quite common to reason through an extensive chain of causal relations. When the lights go out we might reason in the following causal chain: lights out—power off—refrigerator not working—temperature will rise—milk will sour. In other words, we diagnose a succession of effects from the power failure, each becoming the cause of the next.
? ?Causes are classified as necessary, sufficient, or contributory. A necessary cause is one which must be present for the effect to occur, as combustion is necessary to drive a gasoline engine. A sufficient cause is one which can produce an effect unaided, though there may be more than one sufficient cause: a dead battery is enough to keep a car from starting, but faulty spark plugs or an empty gas tank will have the same effect. A contributory cause is one which helps to produce an effect but cannot do so by itself, as running through a red light may. help cause an accident, though other factors--pedestrians or other cars in the intersection—must also be present.
? ?In establishing or refuting (驳倒) a causal relation it is usually necessary to show the process by which the alleged (所谓的) cause produces the effect. Such an explanation is called a causal process.

According to the passage, to do the "effect to effect" reasoning is to reason ______.

A:from cause to effect B:from effect to cause C:from effect to effect and on to cause D:from effect to cause and on to another effect

? ?下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。请仔细阅读短文，并根据短文回答其后面的问题，从4个选项中选择1个最佳答案。
{{B}}第一篇{{/B}}

? ?Another common type of reasoning is the search for causes and results. We want to know whether cigarettes really do cause lung cancer, what causes malnutrition, the decay of cities, or the decay of teeth. We are equally interested in effects: what is the effect of sulphur of lead in the atmosphere, of oil spills and raw sewage in rivers and the sea, of staying up late on the night before an examination?
? ?Causal reasoning may go from cause to effect or from effect to cause. Either way, we reason from what we know to what we want to find out, Sometimes we reason from an effect to a cause and then on to another effect. Thus, if we reason that because the lights have gone out, the refrigerator won’t work, we first relate the effect (lights out) to the cause (power off) and then relate that cause to another effect (refrigerator not working). This kind of reasoning is calls, for short, effect to effect. It is quite common to reason through an extensive chain of causal relations. When the lights go out we might reason in the following causal chain: lights out—power off—refrigerator not working—temperature will rise—milk will sour. In other words, we diagnose a succession of effects from the power failure, each becoming the cause of the next.
? ?Causes are classified as necessary, sufficient, or contributory. A necessary cause is one which must be present for the effect to occur, as combustion is necessary to drive a gasoline engine. A sufficient cause is one which can produce an effect unaided, though there may be more than one sufficient cause: a dead battery is enough to keep a car from starting, but faulty spark plugs or an empty gas tank will have the same effect. A contributory cause is one which helps to produce an effect but cannot do so by itself, as running through a red light may. help cause an accident, though other factors--pedestrians or other cars in the intersection—must also be present.
? ?In establishing or refuting (驳倒) a causal relation it is usually necessary to show the process by which the alleged (所谓的) cause produces the effect. Such an explanation is called a causal process.

Your refrigerator is not working and you have found that the electric power has been cut off. The power failure is a ______.

A:necessary cause B:sufficient cause C:contributory cause D:none of them