GRE阅读练习每日一篇(四十一)_GRE阅读

GRE阅读练习每日一篇(四十一)

　　16. The passage provides information for answering which of the following questions?

　　What causes warm-water vents to form?

　　Do vent faunas consume more than do deep-sea faunas of similar size?

　　Do bacteria live in the vent water of smokers?

　　What role does hydrogen sulfide play in chemosynthesis?

　　What accounts for the locations of deep-sea smokers?

　　17. The information in the passage suggests that the majority of deep-sea faunas that live in nonvent habitats have which of the following characteristics?

　　They do not normally feed on particles of food in the water.

　　They are smaller than many vent faunas.

　　They are predators.

　　They derive nutrition from a chemosynthetic food source.

　　They congregate around a single main food source.

　　18. The primary purpose of the passage is to

　　describe a previously unknown natural phenomenon

　　reconstruct the evolution of a natural phenomenon

　　establish unequivocally the accuracy of a hypothesis

　　survey explanations for a natural phenomenon and determine which is best supported by evidence

　　entertain criticism of the author s research and provide an effective response

　　19. Which of the following does the author cite as a weakness in the argument that bacterial chemosynthesis provides the foundation for the food chains at deep-sea vents?