大學英語四級閱讀訓練題及答案解析

　　閱讀理解是英語四級考試中十分重要的題型，需要考生多做練習提高閱讀理解能力。下面小編為大家帶來大學英語四級閱讀訓練題解析，供考生備考練習。

　　大學英語四級閱讀訓練題原文

　　The Earth comprises three principal layers: the dense, iron-rich core, the mantle made of silicate ***矽酸鹽*** that are semi-molten at depth, and the thin, solid-surface crust There are two kinds of crust, a lower and denser oceanic crust and an upper，lighter continental crust found over only about 40 percent of the Earth's surface. The rocks of the crust are of very different ages. Some continental rocks are over 3,000 million years old, while those of the ocean floor are less than 200 million years old. The crusts and the top, solid part of the mantle, totaling about 70 to 100 kilometers in thickness, at present appear to consist of about 15 rigid plates, 7 of which are very large. These plates move over the semi-molten lower mantleto produce all of the major topographical***地形學的***features of the Earth. Active zones where intense deformation occur are confined to the narrow, interconnecting boundaries of contact of the plates.

　　There are three main types of zones of contact: spreading contacts where plates move apart, converging contacts where plates move towards each other, and transform contacts where plates slide past each other. Newoceanic crust is formed along one or more margins of each plate by material issuing from deeper layers of the Earth' s crust, for example, by volcanic eruptions ***爆發*** of lava ***火山熔岩*** at mid-ocean ridges. If at such a spreading contact the two plates support continents，a rift***裂縫*** is formed that will gradually widen and become flooded by the tea. The Atlantic Ocean formed like this as the American and Afro-European plates moved in opposite directions. When two plates carrying continents collide, the continental blocks,too light to be drawn down, continue to float and therefore buckle ***起褶皺*** to form a mountain chain along the length of the margin of the plates.

　　大學英語四級閱讀訓練題

　　1.The Earth’s crust______.

　　A.can be classified into two types

　　B.is formed along the margins of the plates

　　C.consists of semi-molten rocks

　　D.is about 70 to 100 kilometers thick

　　2.The 15 plates of the Earth are formed from ___.

　　A.the oceanic crusts and continental crusts

　　B.the crusts and the mantle

　　C.the crusts and the top and solid part of the mantle

　　D.the continental crusts and the solid part of the mantle

　　3.Seriously-deformed zones appear _______

　　A.whenever the crusts move over mantle

　　B.when the plates move towards each other

　　C.in the narrow boundaries where two plates meet

　　D.to be the major topographical feature of the Earth

　　4.According to the second paragraph, the formation of the Atlantic Ocean is the example of_______.

　　A.spreading contacts

　　B.the influence of volcanic eruptions

　　C.converging contacts

　　D.transform contacts

　　5.This passage is probably_______.

　　A.a newspaper advertisement

　　B.a chapter of a novel

　　C.an excerpt from a textbook

　　D.a scientific report of new findings

　　大學英語四級閱讀訓練題答案解析

　　1.[A] 事實細節題。選項A與文章第1段第2句所述一致，為正確答案。此類題可採用排除法。根據第2段第2句的內容可以知道選項B所指的只是地殼中的一種.而不是所有地殼。選項C與文章第1句的內容不符。選項D的主語應該是地殼和上層的地幔，不僅僅是地殼。

　　2.[C] 推理判斷題。此題可定位到第1段倒數第3句。題幹中的15 plates是原文該句中的賓語，且該句的謂語中心詞是consist of***由......組成***，題乾的謂語是are formed from，這意思一致，但題目用的是被動語態。表明答案可從原文該句的主語得到。主語中的top和solid並列修飾part of the mantle。選項C為該句的同義替換，故正確。

　　3.[C] 亊實細節題。選項C是對第1段最後一句的同義改寫。文章中沒有提到選項A中the crusts move over mantle 這種現象;選項B提到的現象在第2段第1句才討論到，與題幹無關;文中也沒有提到嚴重變形的地區是地球的主要地形特徵，因此選項D不正確。

　　4.[A] 亊實細節題。第2段主要分成兩部分：第一部分談板塊活動的三種形式，第二部分分別舉例說明其中在說明spreading contacts時，引用了大西洋的例子："The Atlantic Ocean formed like this..."，所以答案為A。

　　5. [C] 主旨大意題。由本文的語言風格和描述內容可以判定這篇文章既不是商業性的，也不是文學性的同時文中敘述的內容具有科普性質，不可能是太前沿性的，因此A、B、D三項都不正確，選項C為此題答案。