Causes are classified as necessary, sufficient, or contributory(起輔助作用的). 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(火花塞)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.

　　4. 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

　　注：斷電不是冰箱不工作的必要原因，而是原因之一，冰箱壞了也可以導致冰箱不工作。

　　Causes are classified as necessary, sufficient, or contributory(起輔助作用的). 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(火花塞)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.

　　5. This passage mainly discusses ____.

　　A) causal reasoning B) classification of cause

　　C) various types of reasoning

　　D) the causal process

　　注：主題題。文中只提到因果關系推理的幾種操作方法

　　Another common type of reasoning is the search for causes and results. We want to know whether cigarettes really do cause lung cancer, what cause malnutrition(營養(yǎng)不良), the decay of cities, or the decay of teeth. We are equally interested in effects: what is the effect of sulphur or lead in the atmosphere, of oil spills and raw sewage readers how to be popular in with around

　　B) teen-agers how to learn to decide things for themselves

　　C) parents how to control and guide their children

　　D) people how to understand and respect each other

　　7. According to the author, many teen-agers think they are brave enough to act on their own, but, in fact, most of them ____.

　　A) have much difficulty understanding each other

　　B) lack confidence

　　C) dare not cope with problems single-handed

　　D) are very much afraid of getting lost

　　Causes are classified as necessary, sufficient, or contributory(起輔助作用的). 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(火花塞)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.

　　4. 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

　　注：斷電不是冰箱不工作的必要原因，而是原因之一，冰箱壞了也可以導致冰箱不工作。

　　Causes are classified as necessary, sufficient, or contributory(起輔助作用的). 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(火花塞)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.

　　5. This passage mainly discusses ____.

　　A) causal reasoning B) classification of cause

　　C) various types of reasoning

　　D) the causal process

　　注：主題題。文中只提到因果關系推理的幾種操作方法

　　Another common type of reasoning is the search for causes and results. We want to know whether cigarettes really do cause lung cancer, what cause malnutrition(營養(yǎng)不良), the decay of cities, or the decay of teeth. We are equally interested in effects: what is the effect of sulphur or lead in the atmosphere, of oil spills and raw sewage readers how to be popular in with around

　　B) teen-agers how to learn to decide things for themselves

　　C) parents how to control and guide their children

　　D) people how to understand and respect each other

　　7. According to the author, many teen-agers think they are brave enough to act on their own, but, in fact, most of them ____.

　　A) have much difficulty understanding each other

　　B) lack confidence

　　C) dare not cope with problems single-handed

　　D) are very much afraid of getting lost