Final Exam Practice

The diagram illustrates the process of producing coffee, from the initial harvest to the final distribution. The process involves nine main stages.

First, ripe coffee cherries are harvested from the plants and transported to processing facilities. At the next stage, the cherries are carefully sorted and cleaned to remove any damaged fruit, leaves, or debris. They are then pulped, whereby the outer skin is removed to expose the coffee beans inside.

Following this, the beans are washed thoroughly with water, after which they are transferred to fermentation tanks. During fermentation, which may last between 24 and 48 hours, the remaining mucilage is broken down by natural enzymes. Once fermentation is complete, the beans are dried — either under sunlight or using mechanical driers — until the required moisture level is achieved.

Subsequently, the dried beans are processed through hulling and milling machines to remove the parchment layer and polish their surfaces. They are then roasted at high temperatures, a step that is crucial for developing the characteristic flavour and aroma of coffee. Finally, the roasted beans are packaged and distributed to retailers and consumers around the world.

In conclusion, coffee production is a complex, multi-stage process in which the quality of each step significantly influences the taste of the final product.

The flowchart illustrates the process by which raw water is treated and made safe for human consumption. The process consists of nine key stages.

Initially, raw water is drawn from a source such as a river or reservoir through an intake system. Large debris such as leaves and sticks are removed by screens at this stage. Next, chemicals such as aluminium sulphate are added during coagulation, which causes tiny particles to clump together. The clumped particles then grow larger through flocculation, forming visible flocs that sink more easily.

Following this, the water enters sedimentation tanks, where the heavy flocs settle at the bottom and are removed as sludge. The cleaner water above is then passed through filtration systems consisting of layers of sand, gravel, and charcoal, which capture any remaining fine particles and microorganisms. Subsequently, the filtered water is disinfected, typically using chlorine or ultraviolet light, to kill any remaining bacteria and viruses.

Once disinfection is complete, the pH of the water is adjusted to a safe level using lime or carbon dioxide. The treated water is then stored in large reservoirs before finally being distributed through a network of pipes to homes and businesses.

In summary, the water treatment process transforms raw water into safe drinking water through a carefully controlled sequence of physical and chemical stages.

The diagram shows the process of manufacturing cotton fabric, from the initial harvesting of raw cotton to the final packaging of the finished product. Nine main stages are involved in this process.

In the first stage, cotton is picked from the fields, either by hand or using mechanical harvesters. It is then taken to a ginning factory, where seeds and impurities are separated from the cotton fibres. Following ginning, the clean fibres are spun into yarn using spinning machines, which twist the fibres together to form long, continuous threads.

Next, the yarn is woven on large looms to produce fabric. Once weaving is complete, the fabric is dyed in the desired colours using chemical dyes, after which it is subjected to a thorough quality check. Any defective pieces are identified and removed at this stage. The approved fabric then undergoes finishing processes, such as softening, shrinkage control, and pressing, to improve its texture and appearance.

In the final stages, the fabric is cut into standardised lengths or specific shapes as required, and the finished pieces are then packaged and prepared for distribution to garment manufacturers and retailers.

In conclusion, cotton fabric production is a systematic process that transforms raw agricultural material into a finished textile product through a series of mechanical and chemical operations.

The flowchart illustrates the process of manufacturing cement, one of the most widely used construction materials in the world. The process involves nine distinct stages, beginning with the extraction of raw materials and ending with the dispatch of the finished product.

Initially, limestone is mined from quarries using heavy machinery. The extracted rock is then transported to the plant, where it is crushed and ground into a fine powder. At the next stage, this powder is blended with other raw materials such as clay and iron ore to produce what is known as raw meal, which must meet precise chemical specifications.

Following this, the raw meal is fed into a large rotary kiln, where it is heated to temperatures of approximately 1,450 degrees Celsius. At these extreme temperatures, a chemical reaction occurs and clinker — small, hard nodules — is formed. The hot clinker is subsequently transferred to a cooling unit, where it is rapidly cooled by blasts of air to stabilise its chemical structure.

Once cooled, the clinker is ground in a cement mill together with a small proportion of gypsum to produce the final cement powder. The cement is then rigorously tested for quality and strength to ensure it meets industry standards. Finally, it is packed into bags or loaded into bulk tankers and dispatched to construction sites and distributors.

In conclusion, cement manufacturing is a complex industrial process that requires precise control of temperature, chemistry, and material composition at every stage to produce a reliable construction material.

The line graph illustrates the number of internet users per 1,000 people in three regions — Asia, Europe, and the Americas — between 2000 and 2020. Overall, internet usage increased significantly in all three regions over the period, with Asia recording the most dramatic growth.

In 2000, Europe had the highest number of internet users, at approximately 60 per 1,000 people, followed by the Americas at 40 and Asia at just 25. However, Asia's figures grew at a far more rapid pace than the other two regions. By 2005, Asian usage had risen to around 90, and it continued to climb steeply, reaching 380 by 2015 and 520 by 2020 — an increase of nearly twenty times the initial figure.

Europe also showed steady growth, rising from 60 in 2000 to a peak of around 400 by 2015, before levelling off at approximately 400 by 2020. The Americas followed a similar trajectory, increasing from 40 to around 330 over the same period, though growth appeared to slow slightly after 2010.

By 2020, Asia had overtaken both Europe and the Americas by a considerable margin, with usage more than 100 points higher than Europe and nearly 200 points higher than the Americas. In contrast, the gap between Europe and the Americas remained relatively narrow throughout the entire period.

The bar chart compares electricity consumption in terawatt hours (TWh) across five sectors — Residential, Commercial, Industrial, Transport, and Agriculture — in 2010 and 2020. Overall, most sectors recorded an increase in electricity use over the decade, with the exception of the Industrial sector, which saw a slight decline.

In 2010, the Industrial sector consumed the most electricity at 42 TWh, followed by Residential at 35 TWh and Commercial at 28 TWh. The Transport and Agriculture sectors recorded the lowest consumption, at 15 and 10 TWh respectively. By 2020, however, the Residential sector had grown to 48 TWh, making it the highest consumer, while the Industrial sector dropped to 38 TWh — a decrease of 4 TWh compared to the previous decade.

The Commercial sector experienced steady growth, rising from 28 to 35 TWh, while Transport consumption increased noticeably from 15 to 22 TWh — a rise of nearly 47%. Agriculture recorded a modest increase from 10 to 13 TWh.

In contrast to the other sectors, the Industrial sector was the only one to record a decline, which may reflect efficiency improvements or shifts toward less energy-intensive manufacturing. By 2020, it had been overtaken by the Residential sector as the leading consumer of electricity.

The pie chart illustrates the distribution of student enrolment across six faculties at a university in 2023. Overall, Engineering accounted for the largest share of students, while Education had the smallest proportion.

Engineering was the most popular faculty, representing 28% of total enrolment. This was followed closely by Business, which made up 22% of students. Together, these two faculties accounted for exactly half of the student population. Arts and Sciences was the third largest, with an 18% share.

Medicine accounted for 14% of enrolment, making it the fourth most popular faculty. Law and Education had the smallest proportions, representing 10% and 8% respectively. Notably, the combined enrolment of Law and Education (18%) was equal to that of Arts and Sciences alone, highlighting the relative unpopularity of these two faculties compared to STEM and Business fields.

In summary, the majority of students — over 60% — were enrolled in Engineering, Business, or Arts and Sciences, with the remaining faculties sharing the rest of the student population in roughly equal proportions.

The line graph compares the CO₂ emissions per capita (measured in kilograms) of China and the USA from 1990 to 2020. Overall, the two countries showed contrasting trends: China's emissions rose significantly over the period, while the USA's followed a general downward trajectory.

In 1990, the USA recorded substantially higher emissions at approximately 520 kg per capita, compared to China's figure of around 220 kg. The USA's emissions increased slightly between 1990 and 2005, peaking at around 600 kg, before beginning a steady decline. By 2020, US emissions had fallen to approximately 460 kg — a decrease of roughly 60 kg from the 2005 peak.

In stark contrast, China's CO₂ emissions grew rapidly throughout most of the period. From 220 kg in 1990, they climbed steeply to a peak of approximately 800 kg by 2015 — an increase of over 260%. After this peak, Chinese emissions declined slightly to around 780 kg by 2020.

Despite China's dramatic increase, the gap between the two countries narrowed considerably over the period. Whereas in 1990 the difference was approximately 300 kg, by 2020 this gap had closed to around 320 kg. The two countries' emissions appeared to be converging, with the possibility of China's per capita figures exceeding those of the USA in the near future if current trends continue.