2012GMAT逻辑推理训练内容希望考生充分利用，总结做题技巧，充分备考。
The reason much refrigerated food spoils is that it ends up out of sight at the back of the shelf. So why not have round shelves that rotate? Because such rotating shelves would have just the same sort of drawback, since things would fall off the shelves' edges into the rear corners.
Which of the following is presupposed in the argument against introducing rotating shelves?
(A) Refrigerators would not be made so that their interior space is cylindrical.
(B) Refrigerators would not be made to have a window in front for easy viewing of their contents without opening the door.
(C) The problem of spoilage of refrigerated food is not amenable to any solution based on design changes.
(D) Refrigerators are so well designed that there are bound to be drawbacks to any design change.(A)
(E) Rotating shelves would be designed to rotate only while the refrigerator door was open.
Archaeologists have found wheeled ceramic toys made by the Toltec, twelfth-century inhabitants of what is now Veracruz. Although there is no archaeological evidence that the Toltec used wheels for anything but toys, some anthropologists hypothesize that wheeled utility vehicles were used to carry materials needed for the monumental structures the Toltec produced.
Which of the following, if true, would most help the anthropologists explain the lack of evidence noted above?
(A) The Toltec sometimes incorporated into their toys representations of utensils or other devices that served some practical purpose.
(B) Any wheeled utility vehicles used by the Toltec could have been made entirely of wood, and unlike ceramic, wood decays rapidly in the humid climate of Veracruz.
(C) Carvings in monument walls suggest that the Toltec's wheeled ceramic toys sometimes had ritual uses in addition to being used by both children and adults as decorations and playthings.
(D) Wheeled utility vehicles were used during the twelfth century in many areas of the world, but during this time wheeled toys were not very common in areas outside Veracruz.(B)
(E) Some of the wheeled ceramic toys were found near the remains of monumental structures.
It would cost Rosetown one million dollars to repair all of its roads. In the year after completion of those repairs, however, Rosetown would thereby avoid incurring three million dollars worth of damages, since currently Rosetown pays that amount annually in compensation for damage done to cars each year by its unrepaired roads.
Which of the following, if true, gives the strongest support to the argument above?
(A) Communities bordering on Rosetown also pay compensation for damage done to cars by their unrepaired roads.
(B) After any Rosetown road has been repaired, several years will elapse before that road begins to damage cars.
(C) Rosetown would need to raise additional taxes if it were to spend one million dollars in one year on road repairs.
(D) The degree of damage caused to Rosetown's roads by harsh weather can vary widely from year to year.(B)
(E) Trucks cause much of the wear on Rosetown's roads, but owners of cars file almost all of the claims for compensation for damage caused by unrepaired roads.
The chanterelle, a type of wild mushroom, grows beneath host trees such as the Douglas fir, which provide it with necessary sugars. The underground filaments of chanterelles, which extract the sugars, in turn provide nutrients and water for their hosts. Because of this mutually beneficial relationship, harvesting the chanterelles growing beneath a Douglas fir seriously endangers the tree.
Which of the following, if true, casts the most doubt on the conclusion drawn above?
(A) The number of wild mushrooms harvested has increased in recent years.
(B) Chanterelles grow not only beneath Douglas firs but also beneath other host trees.
(C) Many types of wild mushrooms are found only in forests and cannot easily be grown elsewhere.
(D) The harvesting of wild mushrooms stimulates future growth of those mushrooms.(D)
(E) Young Douglas fir seedlings die without the nutrients and water provided by chanterelle filaments.
Two experimental garden plots were each planted with the same number of tomato plants. Magnesium salts were added to the first plot but not to the second. The first plot produced 20 pounds of tomatoes and the second plot produced 10 pounds. Since nothing else but water was added to either plot, the higher yields in the first plot must have been due to the magnesium salts.
Which of the following, if true, most seriously weakens the argument above?
(A) A small amount of the magnesium salts from the first plot leached into the second plot.
(B) Tomato plants in a third experimental plot, to which a high-nitrogen fertilizer was added, but no magnesium salts, produced 15 pounds of tomatoes.
(C) Four different types of tomatoes were grown in equal proportions in each of the plots.
(D) Some weeds that compete with tomatoes cannot tolerate high amounts of magnesium salts in the soil.(E)
(E) The two experimental plots differed from each other with respect to soil texture and exposure to sunlight.
上面是2012GMAT逻辑推理训练，希望对考生备考有所帮助。
