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题目： Homeowner Representative: Statistics show that burglars often target houses that appear unoccupied. Therefore, when homeowners are away from their homes for several days, we recommend that they leave lights on, to give the impression that the house is occupied. Crime Expert: The same lights continuously on all night long with no change give a potential burglar a clear signal that the house is unoccupied. The Crime Expert uses which of the following techniques in responding to the Homeowner Representative?

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Eurasian watermilfoil, a weed not native to Frida Lake, has reproduced prolifically since being accidentally introduced there. In order to eliminate the weed, biologists proposed treating infested parts of the lake with a certain herbicide that is nontoxic for humans and aquatic animals. However, the herbicide might damage populations of certain rare plant species that the lake contains. For this reason local officials rejected the proposal.

Which of the following, if true, points out the most serious weakness in the officials' grounds for rejecting the biologists' proposal?

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Last year a record number of new manufacturing jobs were created. Will this year bring another record? Well, any new manufacturing job is created either within an existing company or by the start-up of a new company. Within existing firms, new jobs have been created this year at well below last year's record pace. At the same time, there is considerable evidence that the number of new companies starting up this year will be no higher than it was last year and there is no reason to think that the new companies starting up this year will create more jobs per company than did last year's start-ups. So clearly, the number of new jobs created this year will fall short of last year's record.

In the argument given, the two portions in boldface play which of the following roles?

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Highway Official: When resurfacing our concrete bridges, we should use electrically conductive concrete (ECC) rather than standard concrete. In the winter, ECC can be heated by passing an electric current through it, thereby preventing ice buildup. The cost of the electricity needed is substantially lower than the cost of the de-icing salt we currently use.

Taxpayer: But construction costs for ECC are much higher than for standard concrete,so your proposal is probably not justifiable on economic grounds.

Which of the following, if true, could best be used to support the highway official's proposal in the face of the taxpayer's objection?

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Because it was long thought that few people would watch lengthy televised political messages, most televised political advertisements, like commercial advertisements, took the form of short messages. Last year, however, one candidate produced a half-hour-long advertisement. During the half hour the advertisement was aired, a substantial portion of the viewing public tuned into the advertisement. Clearly, then, many more people are interested in watching lengthy televised political messages than was previously thought.

Which of the following is an assumption on which the argument depends?

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Criminologist: Some legislators advocate mandating a sentence of life in prison for anyone who, having twice served sentences for serious crimes, is subsequently convicted of a third serious crime. These legislators argue that such a policy would reduce crime dramatically, since it would take people with a proven tendency to commit crimes off the streets permanently. What this reasoning overlooks, however, is that people old enough to have served two prison sentences for serious crimes rarely commit more than one subsequent crime. Filling our prisons with such individuals would have exactly the opposite of the desired effect, since it would limit our ability to incarcerate younger criminals, who commit a far greater proportion of serious crimes.

In the argument as a whole, the two boldfaced portions play which of the following roles?

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Educational Theorist: Recent editorials have called for limits on the amount of homework assigned to children. They point out that free-time activities play an important role in childhood development and that large amounts of homework reduce children's free time, hindering their development. But the average homework time for a ten year old, for example, is little more than 30 minutes per night. Clearly, therefore, there is no need to impose the limits these editorials are calling for.

Which of the following is an assumption on which the educational theorist's argument relies?

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Secret passwords are often used to control access to computers. When employees are allowed to make up their own passwords, they are likely to setup as passwords their initials or birth dates. To improve security, employers should assign randomly generated passwords to employees rather than allowing employees to make up their own

Which of the following, if true, most seriously undermines the conclusion drawn above?

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It is crucially important to farmers that the herbicides they use to control weeds do not damage their crops. One very effective herbicide is safe for corn, but soybeans are damaged even by the herbicide's residue, which remains in the soil more than a year after the herbicide is applied. Soybeans and corn are not sown together in the same field; nevertheless, most farmers are reluctant to use the herbicide on their corn.

Which of the following, if true, provides the strongest justification for the farmers' reluctance?

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Rail Executive: Five years ago we discontinued train service between Lamberton and its suburbs because low ridership caused total fares collected to be substantially lower than the cost of operating the service. It is true that recent population growth in the suburban communities suggests increased potential ridership. Nevertheless, since most of the newer residents own automobiles, restoring the train service this year would still result in serious deficits

Which of the following ,if true casts the most serious doubt on the rail executive's argument?

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题目：

The passage suggests that the presence of G10 garnet in a kimberlite pipe indicates that

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题目： If n is a nonzero integer, is $$x^n < 1$$?(1) $$x \gt 1$$(2) $$n \gt 0$$

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题目： Square ABCD pictured to the right has an area of 9 square inches. Sides AD and BC are lengthened to x inches each. By how many inches were sides AD and BC lengthened?(1) The diagonal of the resulting rectangle measures 5 inches.(2) The resulting rectangle can be cut into three rectangles of equal size.

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题目： What is the value of x?(1) $$x^{ 2} – 5 x + 6 = 0$$(2) x > 0

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题目： What is x?(1) $$x^2 + 3x + 2 = 0$$(2) $$x \lt 0$$