雅思阅读难句100句(4)

雅思阅读难句100句(4),标签：雅思阅读评分标准与雅思阅读真题下载,http://www.xuehuiba.com

　　57. It is possible to make specific complementary DNA's （cDNA's）that can serve as molecular probes to seek out the messenger RNA's （mRNA's） of the peptide hormones. If brain cells are making the hormones，the cells will contain these Mrna'S. If the products the brain cells make resemble the hormones but are not identical to them，then the cDNA's should still bind to these mRNA's，but should not bind as tightly as they would to mRNA's for the true hormones. 科学家可以制造出特异的（specific）互补DNA's（cDNA's），以此作为分子探子（molecular probe），探觅出肽激素的信使RNA's（mRNA's）。如果大脑正在制造着肽激素，则细胞就会含有这些信使RNA's.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cDNA's应仍然和这些信使mDNA's粘结的程度。含有这些mRNA's的脑细胞然后就可以被分离开来，研究者可对其信使RNA's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。

　　58. The molecular approach to detecting peptide hormones using cDNA probes should also be much faster than the immunological method because it can take years of tedious purifications to isolate peptide hormones and 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。

　　59. Nevertheless, researchers of the Pleistocene epoch have developed all sorts of more or less fanciful model schemes of how they would have arranged the Ice Age had they been in charge of events. 然而，研究P时代的研究者发展除了各种各样的或多或少有些奇怪思想的模型系统，用来显示如果由他们来决定地质事件的话他们将会如何安排冰川纪。

　　60. This succession was based primarily on a series of deposits and events not directly related to glacial and interglacial periods，rather than on the more usual modern method of studying biological remains found in interglacial beds themselves interstratified within glacial deposits. 这一序列演替（succession）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（interglacial bed）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（interstatified）。

www.xuehuiba.com

　　81. Not only are liver transplants never rejected，but they even induce a state of donor-specific unresponsiveness in which subsequent transplants of other organs, such as skin,from that donor are accepted permanently. 但是，我们已经发现，在许多种老鼠之间，这些移植法的"常规"并没有被肝脏移植物所遵循。肝脏移植物非但从没遭到过排斥，甚至还诱发了一种供者特异性无应答状态（donor-specific unresponsiveness），在此状态中，随后来自那个供者其它器官的移植物，如皮肤，会永久地被接受。

　　82. As rock interface are crossed, the elastic characteristics encountered （by seismic waves）generally change abruptly, which causes part of the energy to be reflected back to the surface, where it is recorded by seismic instruments. 当岩石界面被穿过的时候，震波所遇到的弹性性质通常会发生突然的变化，这就使得一部分能量被反射回地面，在地面反射回来的波被震波纪录仪记录下来。

　　83. While the new doctrine seems almost certainly correct，the one papyrus fragment raises the specter that another may be unearthed，showing，for instance，that it was a posthumous production of the Danaid tetralogy which bested Sophocles,and throwing the date once more into utter confusion. 数据资料已被统计出来，或被重新统计出来，以便证明在文体学这方面，《乞援衰女》实际上确实在《波斯人》和《七雄攻忒拜》（后两者现在则变成了"原始"的剧作）之后以及在轴残片却唤起了一种幽灵似的疑虑，即另一块残片有可能再度被挖掘出来，并证明，比如说，《乞援衰女》是作者藉以击败索福克勒斯的《达那特四部曲》的一部死后出版之作，从而将创作年代再度置于极度的混乱之中. 注：best:击败,=defeat, overcome, outdo

　　84. The methods that a community devises to perpetuate itself come into being to preserve aspects of the cultural legacy that that community perceives as essential. 一个社会所创造出来藉以使其自身生生不息、恒久不衰的方法得以形成产生，以保存在这个社会看来具有本质意义的文化遗产的各个方面。

　　85. Traditionally, pollination by wind has been viewed as a reproductive process marked by random events in which the vagaries of the wind are compensated for by the generation of vast quantities of pollen, so that the ultimate production of new seeds is assured at the expense of producing much more pollen than is actually used. 传统上，风媒传粉被看成是这样的繁殖过程：其特征就是由一些随即事件的发生，在这些随机事件里，风的反复无常被大量的产生花粉所补偿，以至于新种子的最终产生被保证了，其代价是产生远远多于实际使用量的花粉。

上一页  [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]  下一页