GMATOG13、OG12RC部分复习资料.doc

The Official Guide for GMAT* Review 13th Edition 7.4 Sample Questions Each of the reading comprehension questions is based on the content of a passage. After reading the passage answer all questions pertaining to it on the basis of what is stated or implied in the passage. For each question, select the best answer of the choices given. Line Biologists have advanced two theories to explain why schooling of fish occurs in so many fish species. Because schooling is particularly widespread among species of small fish, both theories assume that (5) schooling offers the advantage of some protection from predators. Proponents of theory A dispute the assumption that a school of thousands of fish is highly visible. Experiments have shown that any fish can be seen, (10) even in very clear water, only within a sphere of 200 meters in diameter. When fish are in a compact group, the spheres of visibility overlap. Thus the chance of a predator finding the school is only slightly greater than the chance of the predator finding a single fish (15) swimming alone. Schooling is advantageous to the individual fish because a predators chance of finding any particular fish swimming in the school is much smaller than its chance of finding at least one of the same group of fish if the fish were dispersed (20) throughout an area. However, critics of theory Apoint out that some fish form schools even in areas where predators are abundant and thus little possibility of escaping detection exists. They argue that the school continues (25) to be of value to its members even after detection. They advocate theory B, the confusion effect, which can be explained in two different ways. Sometimes, proponents argue, predators simply cannot decide which fish to attack. This indecision (30) supposedly results from a predators preference for striking prey that is distinct from the rest of the school in appearance. In many schools the fish are almost identical in appearan