Band 8.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 8.5 · Cambridge IELTS 19 · 2026-08-16

IELTS Writing Task 1 question

 

The diagram below shows how a biofuel called ethanol is produced.

Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

Student answer (Band 8.5)

The provided diagram illustrates the cyclical process through which a biofuel known as ethanol is produced, consumed, and naturally recycled within the environment.

Overall, the production and utilization of ethanol is a continuous, multi-stage cycle. It can be broadly categorized into three main phases: the cultivation and harvesting of raw botanical materials, the industrial and chemical conversion of these materials into fuel, and finally, the consumption of the ethanol by vehicles, which emits carbon dioxide back into the atmosphere to sustain future plant growth.

The cycle commences with the agricultural phase, where trees and crops grow by absorbing energy from sunlight alongside carbon dioxide from the atmosphere. Once mature, these plants are harvested using heavy agricultural machinery, such as tractors. Following the harvest, the raw flora undergoes a pre-processing stage in a specialized machine, where it is physically broken down. Notably, this preliminary processing phase releases a small amount of carbon dioxide. The primary output of this mechanical stage is cellulose.

In the subsequent industrial phase, the extracted cellulose is transported to a processing facility where it undergoes chemical refinement to yield basic sugars. Once the sugars are isolated, specific microbes are introduced to facilitate fermentation, ultimately converting the sugary substance into the final biofuel product: ethanol. This ethanol is then distributed to power various modes of transportation, including passenger cars, commercial trucks, and airplanes. During combustion in these vehicles' engines, carbon dioxide is emitted as an exhaust gas. This gas returns to the atmosphere, where it is reabsorbed by growing plants, thereby completing the cycle and initiating the process anew.

AI examiner evaluation

Task Achievement / Task Response — Band 8.5

The response is excellent. It fully addresses all parts of the task by clearly outlining the cyclical nature of ethanol production. The main features, such as the agricultural phase, the industrial conversion, and the final consumption, are accurately identified and logically sequenced. The student successfully highlights the relationship between the stages, including the reabsorption of carbon dioxide, which demonstrates a strong understanding of the process. The overview is clear and provides a concise summary of the entire cycle, meeting the requirements for a high-band response.

Coherence and Cohesion — Band 8.5

The response is logically organized with a clear progression of ideas. Each paragraph serves a distinct purpose, moving smoothly from the introduction to the agricultural phase, then to the industrial phase, and finally to the conclusion. The use of cohesive devices is natural and unobtrusive, such as 'Following the harvest', 'In the subsequent industrial phase', and 'thereby completing the cycle'. Paragraphing is used effectively to separate the different stages of the process, ensuring the reader can easily follow the sequence of events.

Lexical Resource — Band 8.5

The vocabulary is precise, sophisticated, and well-suited to an academic report. The student uses a wide range of topic-specific terminology, such as 'cyclical process', 'botanical materials', 'chemical refinement', and 'fermentation', with high accuracy. The control over collocations is impressive, and the language is used naturally throughout the text. There are no noticeable errors in word choice, and the lexical range is more than sufficient to convey complex information clearly and fluently.

Grammatical Range and Accuracy — Band 8.5

The response demonstrates a wide range of grammatical structures with high levels of accuracy. The student effectively uses complex sentences, such as 'The cycle commences with the agricultural phase, where trees and crops grow by absorbing energy from sunlight alongside carbon dioxide from the atmosphere.' Punctuation is used correctly to manage long, complex sentences, and there are no significant grammatical errors. The control over verb tenses and clause structures is consistent, contributing to the overall clarity and professional tone of the writing.

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