托福听力难在哪?下面是新航道重庆学校教研组老师Sukey给大家带来的解析。

　　托福听力首当其冲就是题目中会涉及天文、地质、物理、化学、历史、艺术等大量学科内容，除了让考生们头大的学科专有名词，还有很多大家日常生活中接触不到的学科知识，大大影响考生们的心态和成绩。

　　但不要担心，托福听力考试中总有高度重复的学科知识，考生们掌握之后，在考场好比打开上帝视角，能轻轻松松做对考题。本期就和Sukey老师一起来看看如何运用地质高频背景知识击破托福听力考题!

　　常考知识——板块构造学(Plate Tectonics)

　　内容：Plate Tectonics

　　板块的转移和移动影响着地球的表面和外观。在板块边界(板块边缘相交的地方)，板块可以分开、碰撞、重叠或滑过。地幔的不均匀加热会导致对流，或是热量的循环使板块四处移动。

　　The shifting and moving of plates affect the earth's surface and appearance. At the plate boundaries (where the edges of plates meet), plates can move apart, collide, overlap, or slide past each other. Uneven heating of the mantle causes convection currents, or the cycling of heat that drags the plates around.

　　Plates Moving Apart

　　分开的板块之间的边界称为离散边界。当板块分离时，地幔中的岩浆被推高，形成新的地壳来填补板块之间的空隙。这种新的岩浆密度低于周围地区，因此它通常会上升并在海底形成海脊。分离的板块也会形成裂谷。

　　The boundary between plates moving apart is called a divergent boundary. When plates move apart, magma from the mantle gets pushed up and forms new crust to fill the gaps between the plates. This new magma is less dense than the surrounding area, so it usually lifts up and forms ridges in the seafloor. Plates that move apart can also form rift valleys.

　　Plates Colliding

　　板块之间相互移动的边界称为汇聚边界。大地震沿着这些边界发生，通常位于地壳深处。板块有两种类型：海洋板块和大陆板块。大洋板块比大陆板块密度大，因此当大洋板块和大陆板块碰撞时，密度较大的大洋板块会沉入地幔中，这一过程称为俯冲。

　　The boundary between plates moving toward each other is called a convergent boundary. Massive earthquakes occur along these boundaries, often deep under the crust. There are two types of plates: oceanic plates and continental plates. Oceanic plates are denser than continental plates, so when an oceanic and a continental plate collide, the denser oceanic plate sinks into the mantle, a process called subduction.

　　Plates Sliding Past Each Other

　　当板块在不同方向上相互滑动时，它们的边缘会刮擦，从而引起地震。地震频发的地方，如加利福尼亚，位于板块边界的顶部。板块相互滑动也会在岩床上形成断层或巨大的裂缝。板块之间相互滑动的边界称为转换边界。

　　When plates slide past each other in different directions, their edges can scrape, causing earthquakes. Places that experience frequent earthquakes, like California, are located on top of plate boundaries. Plates sliding past each other can also form faults, or enormous fractures in the rock bed. The boundary between plates sliding past each other is called a transform boundary.

　　题目(TPO31 LECTURE2 Plate Drift)

　　5. Based on the discussion, what happens when a continental plate and an oceanic plate collide?

　　A. The edge of the oceanic plate moves down into the mantle.

　　B. Slab pull causes the ocean floor to expand.

　　C. New rock material rises to the surface at the subduction zone.

　　D. Parts of each plate break off into the ocean.

　　解析

　　根据本期海洋板块和陆地板块碰撞的相关背景知识“Oceanic plates are denser than continental plates, so when an oceanic and a continental plate collide, the denser oceanic plate sinks into the mantle”，考生们即使没有全部听懂这个段落的内容，也能够选出答案是A选项。

　　以上就是本期有关托福听力运用地质类背景知识解题的讲解，大家都GET了吗?快快练习起来吧!