《剑桥19》Test 3 小作文真题
The diagram illustrates the energy cycle, with an emphasis on the process of producing bioethanol.
In the first stage, plants and trees are grown, absorbing energy from sunlight and carbon dioxide. Once mature, those plants are harvested using agricultural machinery, after which they undergo a pre-processing equipment where they are converted into cellulose, which is a crucial component for ethanol production.
In the following stage, the cellulose is transported into a chemical factory for further processing, and then the starting cellulose is degraded into sugars which are subsequently converted into bioethanol with the addition of microbes. The produced ethanol can be utilized as a fuel for various vehicles, including cars, trucks, and airplanes.
During the combustion of ethanol in engines, carbon dioxide is released into the atmosphere. This carbon dioxide is then reabsorbed by plants and trees, continuing the same procedure cycle.
Overall, the production of bioethanol progresses through a process with eight steps, which begin with photosynthesis employing the carbon dioxide released during the final stage and end in the combustion of ethanol.
剑桥19已经揭开神秘面纱，书中Test 3的小作文是典型的流程图。流程图是考生较为畏惧，实则很简单的一种题型。按照题目要求“selecting and reporting the main features”，流程图的main features包括三个方面，分别是：1. 描述流程以及每两个步骤之间的衔接；2. 流程图所包含的总的步骤数；3. 流程的起始和结束步骤。以上要点中，关键在于每两个步骤之间的衔接，常用的有7种句型，这里先介绍5种，分别是：1. and then引导复合句，给出补充性信息；2. after which引导定语从句；3. 流程图中任意设备都可以抽象成地点，所以可以用where引导的定语从句来衔接上下文；4. before, after, once, when等引导的时间状语从句；5. 副词subsequently衔接。
