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)

　　present evidence that bacterial chemosynthesis may be an inadequate source of food for some vent faunas

　　22. Which of the following can be inferred from the passage about the particulate matter that is carried down from the surface of the ocean?

　　It is the basis of bacterial chemosynthesis in the vents.

　　It may provide an important source of nutrition for vent faunas.

　　It may cause the internal temperature of the vents to change significantly.

　　It is transported as large aggregates of particles.

　　It contains hydrogen sulfide.

　　Throughout human history there have been many stringent taboos concerning watching other people eat or eating in the presence of others. There have been attempts to explain these taboos in terms of inappropriate social relationships either between those who are involved and those who are not simultaneously involved in the satisfaction of a bodily need, or between those already satiated and those who appear to be shamelessly gorging. Undoubtedly such elements exist in the taboos, but there is an additional element with a much more fundamental importance. In prehistoric times, when food was so precious and the on-lookers so hungry, not to offer half of the little food one had was unthinkable, since every glance was a plea for life. Further, during those times, people existed in nuclear or extended family ) groups, and the sharing of food was quite literally supporting one s family or, by extension, preserving one s self.