Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-51

A battery is a common device we use every day to power everything from remote controls to smartphones. But how does this small object store energy? The basic principle is quite simple: a battery doesn't store electrical energy directly. Instead, it holds chemical energy and converts it into electrical energy on demand. (35) __________ a standard battery, there are several key components that work together to make this amazing process happen.

The main parts of a battery are its two terminals, one marked positive (+) and the other negative (-). Separating these terminals is a chemical substance called an electrolyte. When the terminals are connected to a device, like a lightbulb, a chemical (36) __________ takes place inside the battery. This reaction causes tiny particles called electrons to build up at the negative terminal, creating a difference in electrical potential between the two sides.

This difference in potential makes the electrons want to move from the negative terminal to the positive terminal. They travel through the external device in order to get there. This flow of electrons is exactly what we call an electrical current. The battery's internal chemical process is designed specifically to (37) __________ this movement of electrons. The flow creates a complete circuit, (38) __________ allows the battery to power the device.

(39) __________, this process cannot continue forever. The chemical reaction uses up the materials inside the battery. Once the chemicals in the electrolyte are depleted, they can no longer push electrons to the negative terminal. The flow of electrons stops, and we say the battery is 'dead'. This is why the power supply is not (40) __________; it has a limited lifespan determined by its chemical composition.

When you connect a battery to a phone or a toy, you are completing the circuit that allows the electrical (41) __________ to flow and do its work. (42) __________ modern portable electronic device relies on this fundamental principle of converting stored chemical energy into useful electrical energy. Understanding this helps us appreciate the clever science packed into such a small and essential item.

For many teenagers, fashion is a powerful form of self-expression. The thrill of finding a new outfit for a special occasion or simply to wear to school is a familiar feeling. In today's world, there are two dominant paths to update your wardrobe: the fast, trendy world of fast fashion, and the unique, eco-conscious world of thrifting. While both can help you create a great look, the stories behind your clothes reveal very different impacts on our planet, and your choice matters more than you might think.

Fast fashion refers to the business model of producing large quantities of inexpensive clothing in response to the latest trends. Major international brands can design, produce, and stock a new item in just a few weeks. However, this speed and low cost come with a significant environmental price. The industry consumes vast amounts of water and uses chemical dyes that pollute rivers. Furthermore, because the clothes are so cheap, they are often seen as disposable. This leads to an enormous amount of textile waste, with millions of tons of clothing ending up in landfills each year, where they can take hundreds of years to decompose.

In contrast, thrifting, or buying second-hand clothes, offers a compelling alternative. By giving pre-owned items a second life, thrifting directly combats the wastefulness of fast fashion. It's a sustainable practice that conserves resources and reduces the carbon footprint associated with manufacturing new garments. Thrifters often find high-quality, unique pieces that allow them to stand out from the crowd. They believe that personal style doesn't have to cost the Earth, both literally in terms of money and figuratively in terms of environmental damage.

This sustainable trend is gaining significant traction in Vietnam. What was once seen as a necessity for those with limited budgets has now become a cool and conscious choice for many young people, especially in cities like Hanoi and Ho Chi Minh City. A vibrant thrifting culture is growing, with countless online stores on social media and physical markets like '2hand Vina' becoming popular destinations. Young Vietnamese are discovering the joy of hunting for vintage treasures and one-of-a-kind items that reflect their individuality.

Ultimately, the clothes hanging in your wardrobe tell a story. They can tell a story of rapid trends and environmental waste, or one of mindful consumption and unique personal style. As young consumers, understanding the difference between fast fashion and thrifting empowers you to make choices that not only define your look but also reflect your values and your commitment to a healthier planet.