每日一练考研英语必背长难句解析(26)(考研英语每日一练app)

原标题：每日一练 | 考研英语必背长难句解析（26）

51. the best evidence for the layered-mantle thesis is the well-established fact that volcanic rocks found on oceanic islands，islands believed to result from mantle plumes arising from the lower mantle，are composed of material fundamentally different from that of the mid-ocean ridge system， whose source，most geologists contend，is the upper mantle.

译文：关于地幔分层观念来说，最佳的根据乃这样一个招认的实际，即在那些海洋岛屿–这些岛屿据信是源于由基层地幔升上来的地幔柱状溶岩流（mantle plume）–上发现的火山岩石，是由与海洋中部山脊体系的物质根柢不一样的物质构成的，而这一海洋中部山脊体系的成因，大大都地质学家论辩道，为上部地幔。

难句类型：凌乱润饰、刺进语

说明：本句前面的骨干并不算难，即the evidence is the

fact that,难就难在fact 之后阐明fact 的同位语从句。此从句中既有大段刺进语，又有从句，较为难读。同位语从句的主语是volcanic rocks，主语后边的found on oceanic islands 是分词润饰volcanic rocks 的；islands 后边又有一个阐明islands 的同位语islands believed to result from mantle plumes arising from the lower mantle,此同位语实践起到一个分隔主谓的同位语的作用。这今后是谓语动词are composed/of fundamentally different from that of the midocean ridge system, whose source,most geologists contend, is the upper mantle。

句中有一些专有词汇。假定抛开文章不说，单看这一个语句，则句首的layered mantle thesis 就难以了解。可是假定读者可以读懂语句的大致意思，看到layered mantle thesisr 最有力根据就是其材料fundamentally different from… the upper mantle,这大约可以估测出，已然不一样于上层地幔，则这个理论必定是在说地幔有不一样的层面。

练习：the best evidence for the layered-mantle thesis is the well-established fact that volcanic rocks found on oceanic islands，islands believed to result from mantle plumes arising from the lower mantle，are composed of material fundamentally different from that of the mid-ocean ridge system， whose source，most geologists contend，is the upper mantle.

52. some geologists，however，on the basis of observations concerning mantle xenoliths， argue that the mantle is not layered，but that heterogeneity is created by fluids rich in “incompatible elements” （elements tending toward liquid rather than solid state）percolating upward and transforming portions of the upper mantle irregularly，according to the vagaries of the fluids’ pathways.

译文：可是，某些地质学家，以对地幔捕虏岩体（xenolith）所作的调查为根据，指出地幔并非是分层摆放的，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况，自下而上渗透涣散，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有些予以改动。

难句类型：凌乱润饰、刺进语

说明：本句的主句中有一个长刺进语however,on the basis of observations concerning mantle xenoliths,割裂了主谓，但语句的首要难度仍是在that 引导的宾语从句中，从句中有由but 所联接的两个语句，一同连续到句末。首选是rich in incompatible elements 润饰fluids；后边又有一个同位语和一个分词规划，都是润饰incompatible elements 的，最终还有一个状语来润饰那个分词规划，层层润饰，比照凌乱。

练习：some geologists，however，on the basis of observations concerning mantle xenoliths， argue that the mantle is not layered，but that heterogeneity is created by fluids rich in “incompatible elements” （elements tending toward liquid rather than solid state）percolating upward and transforming portions of the upper mantle irregularly，according to the vagaries of the fluids’ pathways.回来搜狐，查看更多

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