PTE Core Writing Test 8

You recently ordered a desk lamp from an online retailer, but the item arrived with a cracked base and the switch does not work. Write an email to the company's customer service department. Describe the problem, explain how it has inconvenienced you, and request either a replacement or a full refund.

Your email is scored on content, form, grammar, vocabulary and spelling.

Summarise the passage in writing.

The concept of circadian rhythms refers to the internal biological clock that governs the timing of physiological processes across a roughly twenty-four-hour cycle. In humans, this clock is regulated primarily by a cluster of neurons in the hypothalamus known as the suprachiasmatic nucleus, which responds to environmental cues, most notably light. When light enters the eye, signals are transmitted to this region, which in turn coordinates the release of hormones such as melatonin and cortisol. Melatonin levels rise in the evening to promote sleep, while cortisol surges in the early morning to support wakefulness and alertness.

Modern lifestyles, however, frequently disrupt these natural rhythms. Exposure to artificial light from electronic devices late at night can suppress melatonin production, delaying the onset of sleep. Shift work, frequent travel across time zones, and irregular sleeping patterns further desynchronise the internal clock from external cues. Research has linked such disruptions to a range of adverse health outcomes, including impaired cognitive performance, weakened immune function, metabolic disorders, and an increased risk of cardiovascular disease. Some studies even suggest correlations between chronic circadian misalignment and certain forms of cancer.

In response, scientists and public health advocates have begun promoting strategies to protect circadian health. These include limiting screen exposure before bedtime, maintaining consistent sleep schedules, and ensuring adequate exposure to natural daylight during waking hours. A growing field known as chronobiology also explores how the timing of meals, medication, and exercise can be optimised to align with the body's internal clock, potentially enhancing both treatment efficacy and overall wellbeing. Understanding and respecting these rhythms is increasingly viewed as essential to long-term health.

Your summary is scored on content, form, grammar and vocabulary.