标题: 大全 Test 19-6、10、15、16 [打印本页] 作者: guang722 时间: 2010-9-5 22:00 标题: 大全 Test 19-6、10、15、16 Damaged nerves in the spinal cord do not regenerate themselves naturally, nor even under the spur of nerve-growth stimulants. The reason, recently discovered, is the presence of nerve-growth inhibitors in the spinal cord. Antibodies that deactivate those inhibitors have now been developed. Clearly, then, nerve repair will be a standard medical procedure in the foreseeable future. Which of the following, if true, casts the most serious doubt on the accuracy of the prediction above? (A) Prevention of the regeneration of damaged nerves is merely a by-product of the main function in the human body of the substances inhibiting nerve growth. (B) Certain nerve-growth stimulants have similar chemical structures to those of the antibodies against nerve-growth inhibitors. (C) Nerves in the brain are similar to nerves in the spinal cord in their inability to regenerate themselves naturally. (D) Researchers have been able to stimulate the growth of nerves not located in the spinal cord by using only nerve-growth stimulants. (E) Deactivating the substances inhibiting nerve growth for an extended period would require a steady supply of antibodies.
选A。不太明白。
Magnetic resonance imaging (MRI)—a noninvasive diagnostic procedure—can be used to identify blockages in the coronary arteries. In contrast to angiograms—the invasive procedure customarily used—MRI’s pose no risk to patients. Thus, to guarantee patient safety in the attempt to diagnose arterial blockages, MRI’s should replace angiograms in all attempts at diagnosing coronary blockages. Which of the following, if true, would most support the recommendation above? (A) Angiograms can be used to diagnose conditions other than blockages in arteries. (B) MRI’s were designed primarily in order to diagnose blockages in the coronary arteries. (C) Angiograms reveal more information about the nature of a blockage than an MRI can. (D) An MRI is just as likely as an angiogram to identify an arterial blockage. (E) Some patients for whom an angiogram presents no risk are unwilling to undergo an MRI.
选D。我觉得选E。虽然E看起来逻辑不对，但是我觉得好像还是。
Over the last century, paleontologists have used small differences between fossil specimens to classify triceratops into sixteen species. This classification is unjustified, however, since the specimens used to distinguish eleven of the species come from animals that lived in the same area at the same time. Which of the following, if true, would enable the conclusion of the argument to be properly drawn? (A) Not every species that lived in a given area is preserved as a fossil. (B) At least one individual of every true species of triceratops has been discovered as a fossil specimen. (C) No geographical area ever supports more than three similar species at the same time. (D) In many species, individuals display quite marked variation. (E) Differences between fossil specimens of triceratops that came from the same area are no less distinctive than differences between specimens that came from different areas.
选C。
Many consumers are concerned about the ecological effects of wasteful packaging. This concern probably explains why stores have been quick to stock new cleaning products that have been produced in a concentrated form. The concentrated form is packaged in smaller containers that use less plastic and require less transportation space. Which of the following, if true, most seriously undermines the explanation offered above? (A) Few consumers believe that containers of concentrated cleaning products are merely small packages of regular cleaning products. (B) The containers in which concentrated cleaning products are packaged are no harder to recycle than those in which regular cleaning products are packaged. (C) Those concentrated cleaning products that are intended to be used diluted have clear instructions for dilution printed on their labels. (D) The smaller containers of concentrated cleaning products enable supermarkets and drugstores to increase their revenues from a given shelf space. (E) Consumer pressure has led to the elimination of wasteful cardboard packaging that was used for compact discs.
(D) An MRI is just as likely as an angiogram to identify an arterial blockage. (E) Some patients for whom an angiogram presents no risk are unwilling to undergo an MRI.