High-Q | English פסיכומטרי

Unit 7

16. The author uses the phrase “a curious phenomenon” (line 18) in order to stress -

(1) the absence of a reasonable income system for retirement (2) the contrast he sees in the present situation (3) the flexibility of retirement (4) unattractive aspects of retirement

17. One of the possible reasons for the low incomes of retired people is -

(1) (2)

the derogatory aspect of retirement

the great loss people tend to feel when they retire

(3) the fact they were not prepared to cope with retirement (4) the need to reserve a pool of potential workers

Text II (Questions 18-22)

Common sense dictates that if you want to flush out indoor air pollutants - from cigarette smoke and spores to gases from cleaning products - you should step up a room's ventilation. But that's not necessarily so, says a new study. Mechanical-engineering experts found that air entering a room through a typical vent flows in turbulently and unevenly. Some of the fresh air rushes through, while some 5 of the stale air already in the room forms stagnant pockets in which pollutants become trapped. Adrian Bejan of Duke University and Jose Lage of Southern Methodist University used a supercomputer at Cornell's Theory Center to model the movement of pollutants in a room under varying conditions. The two-dimensional simulation predicted how 10 pollutants from a single source, such as a burning cigarette, spread within a room in which air moved from a vent on one wall to another vent on the opposite wall. The scientists also simulated a room in which a contaminant was evenly dispersed. “Our question was so basic that we thought if contaminant entrapment is a real phenomenon, then we should see it, especially in two-dimensional air-flow,” Bejan 15 explains. In both situations, says Bejan, some of the contaminant remained in stagnant air cells, while new, fresh air flowed around it. These cells, he explains, “are just like the eye of a hurricane. Air in the middle of them just rolls around, and only very slowly diffuses into the faster-moving air stream”. 20 most effective at removing pollutants when it was directed diagonally at the center of the room. “The air jet has to be aimed at the heart of what would otherwise be one of these persistent cells”, says Bejan. By repositioning the simulated vents, Bejan and Lage found that the airflow was

But even more effective, he adds, are rooms equipped with a slow, steady sheet of moving air. For example, relatively cool air could sink through a porous ceiling through 25

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