Task Achievement
Band 9.0The overview identifies the process structure and the report covers all major stages accurately.
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IELTS Academic
Change examWriting task
The diagram below shows how ethanol biofuel is produced from plant material and used as a transport fuel. Summarize the information by selecting and reporting the main features, and make comparisons where relevant. Write at least 150 words.
Question 1
Sample response
The diagram illustrates a cyclical process in which plant matter is converted into ethanol and ultimately used to power several forms of transport. Overall, biofuel production comprises a sequence of mechanical, chemical and biological stages, beginning with plant growth and ending with combustion. A notable feature is that the carbon dioxide released by vehicles is reused during the next period of growth. Initially, plants and trees develop by absorbing carbon dioxide from the air and energy from sunlight. Once mature, this biomass is harvested and preprocessed, which involves chopping and crushing it into smaller pieces. Cellulose is then isolated from the prepared material. In the next stage, enzymes are added to break this cellulose down into simple sugars. The resulting sugar mixture is transferred to a fermentation vessel, where yeast or other microbes convert it into alcohol. After fermentation, the ethanol is purified so that it can be used as fuel. The finished product powers cars, trucks and aircraft. These vehicles emit carbon dioxide, but rather than representing a purely linear endpoint, this gas returns to the atmosphere and is absorbed by new plants, thereby completing the cycle.
Evaluation
This response gives a precise overview, selects every essential stage, and groups the process logically without speculation.
The overview identifies the process structure and the report covers all major stages accurately.
Stages are grouped into purposeful paragraphs and links express sequence without sounding mechanical.
Process vocabulary is precise, varied, and natural.
Controlled passive forms and complex sentences describe the process with high accuracy.
Sample response
The picture shows how plants can become fuel. First, plants and trees grow because there is sun and carbon dioxide. After they are ready, people harvest them and the material is cut and crushed. Then cellulose is taken from it. Enzymes are added so the cellulose changes into sugar. Next, microbes are used for fermentation and this makes ethanol. The ethanol is cleaned and after that it can be put in different vehicles. The picture gives examples of a car, a truck and an airplane. These vehicles use the fuel and carbon dioxide goes into the air again. Overall, there are many steps and it starts with plants and finishes with vehicles. This is useful because fuel is needed for transport. The carbon dioxide can also help more plants to grow, so the process can happen again.
Evaluation
The sequence is mostly accurate, but the overview is vague and the response adds an unsupported opinion about usefulness. Development and vocabulary are limited.
The response mentions several visible stages but the overview or coverage is incomplete.
The order is generally understandable, although progression is repetitive or uneven.
Vocabulary communicates the basic process but repetition and imprecise choices limit the score.
Simple sentences are usually understandable, but errors and limited range reduce control.