Đề ôn thi Đề thi vào lớp 10 Trường Phổ thông Năng khiếu môn Tiếng Anh - Mã đề PTNK-59

Building tunnels under rivers presents a major engineering challenge. Today, engineers use giant machines called Tunnel Boring Machines, or TBMs. These are like underground factories that dig and build the tunnel simultaneously. Not only do they excavate rock and soil, but they also install the tunnel lining immediately behind them, making the process highly efficient.

The first step is to launch the TBM from a large, deep shaft built on one side of the river. The (21) __________ machine, which can be hundreds of metres long, has a rotating cutting head at its front. As this head turns, it grinds away the earth. The dug-out material, known as muck, is then transported back to the surface through a system of conveyor belts, keeping the path ahead clear.

As the TBM moves forward, pre-made curved concrete segments are brought to the front. A robotic arm then lifts and places these segments to form a complete, solid ring. (22) __________ completes the structural support for a new section of the tunnel. Then, using hydraulic jacks, the TBM pushes against this new ring to advance itself further. This entire cycle is repeated continuously, metre by metre.

A tunnel built beneath a river must be completely waterproof to prevent any leaks. To achieve this, special seals are placed between each of the concrete segments as they are installed. The external pressure from the water and soil above is immense, so the tunnel structure is specifically designed to withstand this force. The round shape of the tunnel is the most effective design for distributing this pressure evenly.

(23) __________, the construction of an underwater tunnel is a complex, step-by-step process that combines powerful machinery with precise engineering. The (24) __________ completion of these vital infrastructure projects helps to connect cities and make transportation more efficient, demonstrating the remarkable capabilities of modern engineering.

The sun feels fantastic on your skin, especially when you're out with friends, playing sports, or enjoying a day at the beach. Many people associate sun exposure with a healthy glow or a desirable tan. [I] Beneath the warmth and light, ultraviolet (UV) rays are at work, and their effects can be far-reaching, extending well beyond a summer tan. Understanding these impacts is crucial for your long-term health.

[II] Globally, dermatologists are sounding the alarm about the serious, long-term consequences of unprotected sun exposure. [III] It’s not just about getting sunburned; repeated exposure, even when it doesn't cause a noticeable burn, can lead to significant problems. These include premature skin aging, resulting in wrinkles and sunspots appearing much earlier than they should. More concerningly, it dramatically increases the risk of skin cancer, including melanoma, which can be life-threatening. These harmful UV rays even penetrate clouds, meaning you're still at risk on overcast days.

In a tropical country like Vietnam, sun protection is especially critical. The intense equatorial sun means that UV levels are consistently high, making everyday outdoor activities potentially damaging. This awareness is deeply ingrained; it’s common to see people, especially women, wearing "áo chống nắng" – full-coverage sun protection jackets – while driving or walking. Furthermore, a market is full of specialized sun care products, with popular brands like Sunplay leading the way, highlighting a collective understanding of the need for effective sun defense.

You might think skin damage is a future worry, but protecting your skin now, during adolescence, is a vital investment in your health. [IV] Your skin remembers every bit of sun exposure, and damage accumulates over time. This is why understanding terms like SPF (Sun Protection Factor) and how to apply sunscreen correctly is such an important life skill. Whether you're playing football, riding your bike, or heading to the beach, consistently using a broad-spectrum sunscreen with an adequate SPF, and reapplying it regularly, is essential.

Ultimately, embracing sun protection isn't about avoiding the outdoors; it's about enjoying it safely and smartly. By making simple habits like applying sunscreen and seeking shade part of your routine, you are actively safeguarding your skin's health and appearance for years to come. Your skin is your body’s largest organ, and taking care of it today means a healthier, more vibrant you tomorrow.