READING PASSAGE 1

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.

Innovations in Energy Storage

Energy storage is critical for renewable energy integration, but finding sustainable and efficient solutions remains a challenge

A. The quest for efficient and sustainable energy storage solutions has become paramount as the world shifts towards renewable energy sources. Batteries, particularly lithium-ion types, have been the cornerstone of this development. However, the mining of lithium and other rare metals poses significant environmental concerns due to its impact on ecosystems, water resources, and pollution levels. As renewable energy production increases, the need for better storage solutions becomes more urgent to ensure a stable and reliable power supply.

B. One of the primary challenges in replacing traditional energy storage methods is the efficiency and capacity of alternatives. Dr. Angela Perez, a leading researcher at the National Renewable Energy Laboratory, notes that while lithium-ion batteries have their drawbacks, they offer unmatched energy density and rechargeability. “Lithium-ion batteries are not perfect,” Perez admits, “but they currently provide the best balance of performance and cost.”

C. New materials and technologies are being explored to overcome the limitations of current energy storage solutions. Solid-state batteries, which use solid electrolytes instead of liquid ones, promise higher energy densities and better safety. Additionally, research into flow batteries, which store energy in liquid electrolytes contained in external tanks, suggests they could provide scalable and long-lasting solutions for large-scale energy storage needs.

D. Another promising area of research is hydrogen fuel cells. By converting hydrogen into electricity, these cells offer a clean energy storage option. Hydrogen can be produced using renewable energy sources and stored in large quantities, making it a viable alternative for balancing supply and demand in power grids. Markus Mannström, a renewable energy expert, highlights that several countries are investing heavily in hydrogen infrastructure to support this transition, recognizing its potential in creating a more sustainable energy future.

E. Despite their potential, hydrogen fuel cells face several hurdles. Hydrogen storage requires high pressure and low temperatures, which can be costly and technically challenging. Moreover, the production of hydrogen itself, typically through electrolysis, needs to become more efficient and cost-effective. Researchers are working on advanced catalysts and new methods to address these issues, aiming to make hydrogen a mainstream energy storage solution. As Anna Surgenor highlights, "The development of advanced catalysts in hydrogen production is critical to overcoming current efficiency barriers and making hydrogen a viable, scalable energy option for the future.

F. Another innovative approach involves the use of supercapacitors, which store energy in an electric field rather than through chemical reactions. Julie Miles, an energy storage specialist, explains: "Supercapacitors have the ability to charge and discharge quickly, providing a high power output. While they cannot store as much energy as batteries, they are ideal for applications requiring quick bursts of power, such as in electric vehicles and grid stability services.

G. Researchers are also exploring the use of gravity-based energy storage systems. These systems store energy by lifting heavy objects and then releasing them to generate electricity as they fall. This method is highly sustainable and relies on simple mechanics, offering a low-maintenance and long-lasting solution. However, it requires significant infrastructure and space, which limits its applicability in densely populated areas.

H. While the future of energy storage holds many exciting possibilities, it also presents numerous challenges. Felix Preston and Johanna Lehne of the International Institute for Sustainable Development highlight that, “Innovation in energy storage is critical, but we must also consider the environmental and social impacts of these new technologies.” As research continues, balancing performance, cost, and sustainability will be key to developing effective energy storage solutions.

READING PASSAGE 2

You should spend about 20 minutes on Questions 14–28, which are based on Reading Passage 2 below.

The Rise and Fall of Electric Vehicles

The development and decline of early electric vehicles

A. Electric vehicles (EVs) were among the first automobiles developed in the late 19th and early 20th centuries. They offered a clean and quiet alternative to the noisy and polluting internal combustion engines of the time. Early EVs were particularly popular in urban areas, where their limited range and lower speed were less of an issue. By the early 1900s, electric cars accounted for a significant portion of the automobile market, especially among the wealthy elite who appreciated their ease of use and lack of manual cranking.

B. The golden era of electric vehicles was short-lived, however. The advent of the internal combustion engine, with its superior range and power, quickly overshadowed electric technology. Innovations such as the electric starter introduced by Cadillac in 1912 eliminated the need for hand cranking, making gasoline cars much more user-friendly.

C. Despite the decline, there were numerous attempts to revive electric vehicles throughout the 20th century. For instance, during the oil crises of the 1970s, interest in alternative energy sources surged. Automakers experimented with various electric models, but the technology of the time could not compete with the performance and convenience of gasoline engines. Battery technology was particularly limiting, offering insufficient range and long charging times.

D. A significant revival attempt occurred in the late 1990s and early 2000s. Companies like General Motors launched models such as the EV1, which garnered a small but enthusiastic following. Despite its advanced technology, the EV1 struggled with high production costs and limited market appeal. General Motors eventually discontinued the EV1 program, citing economic infeasibility and technological barriers.

E. The development of lithium-ion batteries marked a turning point for electric vehicles. These batteries offered significantly higher energy densities, longer life cycles, and faster charging times compared to their predecessors. This breakthrough, coupled with growing environmental concerns and government incentives, led to a renewed interest in EVs. Companies like Tesla spearheaded this revolution, demonstrating that electric cars could be both high-performing and desirable.

F. Modern electric vehicles face fewer of the challenges that plagued their predecessors, but they are not without obstacles. High production costs, limited charging infrastructure, and range anxiety remain significant barriers to widespread adoption. Governments and companies are investing heavily in charging networks and battery technology to address these issues, aiming to make EVs more accessible to the general public.

G. Despite these efforts, the transition to electric vehicles is a complex and ongoing process. Pricing remains a crucial factor, as EVs are generally more expensive than traditional cars due to the cost of batteries. However, advancements in technology and economies of scale are gradually reducing these costs. Many industry experts believe that achieving price parity with gasoline cars will be a tipping point for mass adoption.

H. Looking ahead, the future of electric vehicles seems promising but uncertain. Felix Preston and Johanna Lehne of the International Institute for Sustainable Development point out, “While the potential for EVs to reduce carbon emissions is significant, the transition requires careful planning and consideration of resource availability and environmental impact.” As the automotive industry continues to innovate, the path forward for electric vehicles will depend on balancing technological advances with sustainable practices.

READING PASSAGE 3

You should spend about 20 minutes on Questions 29–40, which are based on Reading Passage 3 below.

The Case for Collaborative Learning

Exploring the benefits and challenges of mixed-ability groups in education

A. Imagine a classroom where students work together on a project, each contributing their unique strengths and learning from one another. This is the essence of collaborative learning, a teaching approach that brings together students of different abilities to achieve common goals. Research suggests that mixed-ability groups can enhance learning experiences by fostering peer support, critical thinking, and social skills. Teachers often use collaborative projects to help students understand complex concepts through discussion and cooperation.

B. The concept of mixed-ability groups is not without its critics. Some educators argue that such groups can hinder the progress of higher-achieving students while overwhelming those who struggle. Dr. Emma Johnson, an education specialist, notes that “the success of mixed-ability groups largely depends on effective classroom management and the ability of the teacher to address diverse learning needs simultaneously.” Balancing the needs of all students in a mixed-ability setting is a challenging but essential task for educators.

C. Despite the challenges, many schools have embraced collaborative learning. Programs designed to encourage teamwork and peer tutoring have shown promising results. For instance, a study conducted by the National Education Association found that students in mixed-ability groups often perform better on standardised tests than those in tracked classes. The study attributes this success to the increased engagement and motivation that collaborative learning fosters.

D. One of the key advantages of mixed-ability groups is the opportunity for peer-to-peer learning. Students who may excel in one subject can help their peers who struggle, reinforcing their own understanding in the process. This reciprocal teaching dynamic benefits both the tutor and the learner. Additionally, working in diverse groups prepares students for real-world situations where they will need to collaborate with individuals of varying skill levels and backgrounds.

E. However, implementing mixed-ability groups effectively requires careful planning and support. Teachers must be equipped with strategies to manage group dynamics and ensure that all students are actively participating. Professional development programs focused on collaborative teaching methods can help educators develop these skills. Furthermore, schools must provide adequate resources, such as classroom materials and time for planning, to support successful collaboration.

F. Critics also point out that mixed-ability groups can sometimes lead to disparities in workload and participation. In some cases, higher-achieving students may take on more responsibilities, while others contribute less. To mitigate this issue, educators can use structured activities with clearly defined roles and expectations. Regular assessments and feedback can also help ensure that all students are contributing meaningfully to group tasks.

G. The benefits of collaborative learning extend beyond academic achievement. Working in mixed-ability groups helps students develop essential social skills, such as communication, empathy, and teamwork. These skills are critical for success in both personal and professional contexts. By fostering a supportive and inclusive learning environment, schools can help students build the confidence and resilience needed to navigate future challenges.

H. As education systems continue to evolve, the debate over the effectiveness of mixed-ability groups persists. Felix Preston and Johanna Lehne of the International Institute for Sustainable Development argue that, “Collaboration and inclusivity are key components of modern education, but their implementation must be carefully managed to ensure equity and effectiveness.” The future of collaborative learning will depend on ongoing research, innovation, and a commitment to meeting the diverse needs of all students.