GRE考试《阅读理解》模拟练题2.docxVIP

Word文档下载后（可任意编辑） 第 第 PAGE 1 页 共 NUMPAGES 1 页 GRE考试《阅读理解》模拟练题2  GRE阅读：GRE考试《阅读理解》模拟练题2  GRE核心模考课程  Our study revealed that nest-guarding long-tailed skinks (a species of lizard) homed (returned to their nests) more successfully when displaced shorter distances. There are two reasons why homing success rates decreased with increasing displacement distance. One possibility is that females were simply displaced too far to find their way home. However, this is unlikely given that some individuals managed to find their way home from each distance we used. The second possibility deals with trade-offs between the risks associated with making a long return trip and the benefits of returning. Animals should expend energy only when the associated costs are low. As reptiles increase the time spent moving, their daily energy expenditure increases dramatically. The energetic costs of returning home and the chances that the eggs will have been preyed upon during the return trip both increase substantially as displacement distance increases. For example, the 130 hours (5.5 days) that female skinks spent returning from a distance of 300 meters is sufficient for an egg-eating snake to locate and prey upon the entire clutch. However, females with larger clutches were more likely to home at distances over 50 meters. For these females, the relative fitness benefits associated with having more eggs successfully hatch may outweigh the energetic costs of returning to a nest site, even if the nest may have already been preyed upon.  1. The primary purpose of the passage is to  A. question the validity of research on nest-guarding behavior in long-tailed skinks  B. consider explanations for a finding regarding long-tailed skinks  C. discuss the importance of homing for long-tailed skinks  D. describe the relationship between clutch size and homing success in long-tailed skinks  E. identify the benefits of a behavior common among long-tailed skink