GRE阅读考试难句解读（六）

　　38.Some geologists，however，on the basis of observations concerningmantle　xenoliths，argue that the mantle is　not layered，but thatheterogeneity is created by fluids rich in incompatible elementspercolatingupward and transforming　portions of the uppermantle　irregularly，according to the vagaries of the fluids pathways.

　　但是，某些地质学家，以对地幔捕虏岩体所作的观察为依据，指出地幔并非是分层排列的，相反，地幔的异质性是由那些富含不相容成分的流质构成的，这些成分趋向于流体而非固体的状态，自下而上渗透扩散，并依照这些流质流向的任意性，不规则地将上部地幔的某些部分予以改变。

　　39.The very richness and complexity of the　meaningful relationshipsthat kept　presenting and rearranging themselves　on all levels，fromabstract intelligence to profound dreamy feelings， made it difficultfor Proust to set them out coherently.

　　各种有意义的联系在所有的层次上，自抽象的理性至深刻的梦幻般的情感，层出不穷并不断重新组合排列;正是这些有意义的联系的丰富性和复杂性，致使普鲁斯特难于将它们错落有致地安排好。

　　40.It is possible to make specific complementary DNAsthat can serve as molecular probes to seek out the messengerRNAs of the peptide hormones. If brain cells are making thehormones，the cells will contain these MrnaS. If the products the braincells make resemble the hormones but are not identical to them，then thecDNAs should still bind to these mRNAs，but should not bind astightly as they would to mRNAs for the true hormones.

　　科学家可以制造出特异的互补DNAs，以此作为分子探子，探觅出肽激素的信使RNAs。如果大脑正在制造着肽激素，则细胞就会含有这些信使RNAs.假若细胞所制造的产品类似于肽激素但并非与这些肽激素全然相同，那么，互补cDNAs应仍然和这些信使mDNAs粘结的程度。含有这些mRNAs的脑细胞然后就可以被分离开来，研究者可对其信使RNAs进行解码，以确定它们的蛋白质产品究竟是什么，并确定这些蛋白质产品在何种程度上类似于真正的肽激素。

　　41.The molecular approach to detecting peptide hormones using cDNAprobes should also be much faster than the immunological method becauseit can　take years of tedious purifications to isolate peptide hormonesand then develop antiserums to them.

　　采用cDNA探子来测定肽激素的这一分子生物学方法同时也应该比免疫学的方法速度来得快，因为对于免疫的方法来说，需耗费好几年枯燥的提纯进程，方能将肽素分离了出来，然后再培养出针对它们的抗血清。

　　42.This succession was based primarily on a series of deposits　andevents not directly related to glacial and interglacialperiods，rather than on the more usual modern method of studyingbiological remains found in interglacial beds themselvesinterstratified within glacial deposits.

　　这一序列演替所依据的，主要是一系列与冰川期和间冰期并不直接相关的地质沉积物和地质事件，而不是依据更为普遍的现代方法，去研究间冰层中所发现的生物残留物，而这些间冰层本身又在冰川沉积物发生间层化。