Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-15

A laptop computer is a marvel of modern engineering, packing powerful capabilities into a portable design. It is a complex machine made up of many (35) __________ parts, each with a specific job. Understanding these fundamental components helps users appreciate how these devices work and allows them to make better choices when buying or upgrading their technology. This introduction sets the stage for a detailed look at the key elements.

On the outside, the most obvious components are the screen and the keyboard. The screen, or display, is the primary output device which shows you everything from text and images to videos. Below the screen is the keyboard, the main input device where you (36) __________ type documents, send emails, and navigate software. Attached to the keyboard area is the trackpad, which functions as the mouse, allowing you to control the cursor on the screen.

The true power of a laptop lies inside its case. The Central Processing Unit (CPU) is often described as the computer's brain. (37) __________ does the CPU perform billions of calculations per second, but it also manages the flow of information between all other parts. The successful (38) __________ of tasks, from opening an application to playing a game, depends heavily on the processor's speed and power.

Working closely with the CPU are the memory (RAM) and the hard drive. RAM provides temporary storage for data that is actively being used, and generally, the more RAM a laptop has, the (39) __________ it can handle multiple programs at once without slowing down. For long-term storage, the hard drive is essential. This is the component that must (40) __________ the critical role of permanently saving your operating system, applications, and personal files like photos and documents.

Finally, a laptop would not be portable without its battery, which supplies power when it is not connected to an electrical outlet. The ability to work for hours on a single charge is a key feature. (41) __________ allows users to take their work anywhere. (42) __________, each component, from the visible screen to the internal processor, is vital. They all must work together seamlessly to provide the smooth, functional experience we expect from our laptops.

Across Vietnam, from bustling city convenience stores to quiet street-side stalls, the colorful cans of energy drinks like Red Bull and Sting are a common sight. For many students aged 14 to 15, facing long school days and extra evening classes, these drinks seem like a perfect solution. When you’re feeling exhausted before a big exam, the promise of a quick energy boost can be very tempting. But while these beverages are popular and heavily marketed to young people, it's crucial to look beyond the appealing packaging and ask a critical question: are they a helpful study aid or a significant health gamble?

The immediate feeling of alertness from an energy drink comes from its two main ingredients: caffeine and sugar. Caffeine, a powerful stimulant, works by blocking adenosine, a chemical in the brain that makes you feel tired. This creates a temporary sense of focus and wakefulness. At the same time, the high dose of sugar provides a quick rush of fuel to the body and brain. This is why energy drinks can provide them with a short-term feeling of being able to concentrate and study longer. The combination seems perfect for pushing through a difficult study session.

However, this boost is often short-lived and comes with a downside. The large amount of sugar that provides the initial energy spike is processed very quickly by the body. This leads to a “sugar crash,” a sudden drop in blood sugar levels that can leave you feeling even more tired and less focused than before. Beyond the crash, the high levels of caffeine can cause other negative effects, such as anxiety, a rapidly beating heart, and difficulty sleeping later at night. This can disrupt the very sleep patterns that are essential for memory consolidation and effective learning.

The risks are not just confined to the short term. Regular consumption of these sugary and acidic drinks can lead to serious long-term health problems. The high calorie count with little nutritional value can contribute to weight gain. Furthermore, the combination of sugar and acid can be very damaging to tooth enamel, leading to dental cavities over time. There is also the risk of developing a dependence on caffeine, where a person feels they cannot function normally without it, creating a cycle of fatigue and consumption.

In conclusion, while the immediate benefits of energy drinks are undeniable, the potential health risks, both short-term and long-term, are substantial. The temporary boost they provide often comes at a high price. For students aiming for academic success, a more sustainable approach is far better. Prioritizing a good night’s sleep, staying hydrated with water, eating balanced meals, and taking short, regular breaks from studying are much healthier and more effective strategies for maintaining energy and focus in the long run.