托福听力荟萃 78（在线收听）

Today I want to talk about the Earth's last major____shift, at the end of the last______. Butfirst, let's back up a moment and review what we know about climatic change in general. First, we defined"climate" as_____patterns of weather over significant periodsof time. In general, changes in climate occur when the energy balance of the Earth is______.Solar energy entersthe Earth's atmosphere as light and is______by the Earth's surface asheat. Land, water, and iceeach affect this energy exchange differently. Thesystem is so complex that, to date, our bestcomputer models are only______________and are not sophisticated enough totest______about the causes of climatic change. Ofcourse, that doesn't keep us from_______. For instance, volcanic activity is one mechanism that might affect climatic change. Whenlarge volcanoes erupt, they______tons of particles into the upper atmosphere, where theparticles then reflectlight. Since less light is entering the system of energy exchange, theresultwould be a_______of the Earth's surface. Of course, this is just one possible mechanismof global climate change. In all probability, a complete explanation would involve severaldifferent mechanisms operating at the same time.

【填空答案】

climatic: adj.connected with the weather in a particular area 气候的

iceage: one of the long periods of time,thousands of years ago, when ice covered many northern countries 冰川期，冰河时代

consistent: adj. alwayshaving the same beliefs, behavior, attitudes, quality etc（信仰、行为、态度、品质等）一贯的，一致的；始终如一的

disturb: v. tointerrupt someone so that they cannot continue what they are doing by asking aquestion, making a noise etc 干扰，打扰；使中断

radiate: v. ifsomething radiates light or heat, or if light or heat radiates from something,it is sent out in all directions 辐射（光或热）；（向四面八方）发射

crude: adj. notdeveloped to a high standard or made with great skill 粗制的

approximation: n. ［C］a number,amount etc that is not exact, but is almost correct 概算，近似值

hypothesis: n. ［C］pluralhypotheses, an idea that is suggested as apossible way of explaining a situation, proving and idea etc, which has not yetbeen shown to be true 假设，假说

speculate: v. to thinkor talk about the possible causes or effects of something without knowing allthe facts or details 猜测，推测

disperse: v. ifsomething disperses or is dispersed, it spreads over a wide area（使）消散；（使）分散

cooling: n.［U］the process ofbecoming cooler; a falling temperature 冷却

【听力原文】

Today I want to talk about the Earth's last major climatic shift, at the end of the last ice age. But first, let's back up a moment and review what we know about climatic change in general. First, we defined "climate" as consistent patterns of weather over significant periods of time. In general, changes in climate occur when the energy balance of the Earth is disturbed.Solar energy enters the Earth's atmosphere as light and is radiated by the Earth's surface asheat. Land, water, and ice each affect this energy exchange differently. The system is so complex that, to date, our best computer models are only crudeapproximations and are not sophisticated enough to test hypotheses about the causes of climatic change. Ofcourse, that doesn't keep us from speculating. For instance, volcanic activity is one mechanism that might affect climatic change. When large volcanoes erupt,they dispersetons of particles into the upper atmosphere, where the particles then reflectlight. Since less light is entering the system of energy exchange, the result would be a cooling of the Earth's surface. Of course, this is just one possible mechanism of global climate change. In all probability, a complete explanation would involve several different mechanisms operating at the same time.

【参考译文】

今天，我想谈谈地球上最后的大气候的转变，在最后一个冰河时代的结束。但首先，让我们备份了一下，回顾我们所知道的关于气候变化的一般。首先，我们定义的“气候”显着的时间段是一致的天气模式。在一般情况下，在气候发生变化时，地球的能量平衡被打乱。太阳能进入地球的大气层作为光，并且由地球表面的辐射热。土地，水和冰的每一个不同的方式影响这个能量交换。该系统是如此复杂的是，到今天为止，我们最好的计算机模型是只原油近似，没有足够的经验来验证假设有关气候变化的原因。当然，这并不让我们的猜测。例如，火山活动是一种机制，可能会影响气候变化。当大的火山爆发，他们分散的粒子进入大气层，其中的粒子反射光吨。由于光线越少进入系统的能量交换，其结果将是地球表面的冷却。当然，这是全球气候变化的一个可能的机制。在所有的可能性中，一个完整的解释会涉及到几种不同的机制，在同一时间。