【数据充分DS】

If k is an integer greater than 1, is k equal to 2r for some positive integer r ?(1) k is divisible by 26.(2) k is not divisible by any odd integer greater than 1.

【数据充分DS】

If w, x, y, and z are integers such that w/x and y/z are integers, is w/x  + y/z odd?(1) wx + yz is odd.(2) wz + xy is odd.

【问题求解PS】

When positive integer x is divided by 5, the remainder is 3; and when x is divided by 7, the remainder is 4.  When positive integer y is divided by 5, the remainder is 3; and when y is divided by 7, the remainder is 4.  If x > y, which of the following must be a factor of x - y? 

【句子改错SC】

Most of Portugal’s 250,000 university students boycotted classes in a one-day strike to protest a law that requires them to contribute $330 a year toward the cost of higher education, previously paying $7 per year.

【句子改错SC】

Critical-thinking instruction is predicted on two assumptions:  that there are clearly identifiable thinking skills that students can be taught to recognize and apply appropriately, and if recognized and applied, students will become more effective thinkers.

【句子改错SC】

The city has proposed a number of water treatment and conservation projects the cost of which raises water bills high enough so that even environmentalists are beginning to raise alarms. 

【句子改错SC】

Not only did the systematic clearing of forests in the United States create farmland (especially in the Northeast) and gave consumers relatively inexpensive houses and furniture, but it also caused erosion and very quickly deforested whole regions. 

【句子改错SC】

The number of plant and animal species that humans are known to have forced to extinction in the last half millennium is over 800.  

【句子改错SC】

Trans World Entertainment Corporation, which owns the Record Town and Saturday Matinee retail chains, announced that since sales of up to one-fourth of its stores are poor, they will be closed.

【句子改错SC】

Leaching, the recovery of copper from the drainage water of mines, as a method of the extraction of minerals, it was well established as early as the eighteenth century, but until about 25 years ago miners did not realize that bacteria take an active part in the process.  

【逻辑CR】

Ozone in the stratosphere blocks deadly ultraviolet rays from the sun, but  chlorofluorocarbons (CFCs) in aerosols and other products have thinned this protective layer.  Evidence of this is the ozone hole that forms over the South Pole every Antarctic spring as  temperatures drop bel...

【逻辑CR】

Most geologists believe oil results from chemical transformations of hydrocarbons derived from organisms buried under ancient seas. Suppose, instead, that oil actually results from bacterial action on other complex hydrocarbons that are trapped within the earth. As is well known, the volume of these...

【逻辑CR】

 Columnist: Metro City has a lower percentage of residents with humanities degrees than any other city of comparable size in our nation. Nationwide, university graduates generally earn more than people who are not university graduates, but those with humanities degrees typically earn less than ...

【逻辑CR】

Manufacturers sometimes discount the price of a product to retailers for a promotion period  when the product is advertised to consumers. Such promotions often result in a dramatic  increase in amount of product sold by the manufacturers to retailers. Nevertheless, the  manufacturers ...

【逻辑CR】

Scientist: In an experiment, dogs had access to a handle they could pull to release food into a nearby enclosure that contained a familiar dog and nothing else, contained an unfamiliar dog and nothing else, or was empty. The dogs typically released more food to the familiar dog than to the unfamilia...