Đề ôn thi Đề thi vào lớp 10 Trường Phổ thông Năng khiếu môn Tiếng Anh - Mã đề PTNK-85

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 (21) __________ 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 massive 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. This 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 (22) __________ 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 (23) __________ effective design for distributing this pressure evenly.

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

The lure of free Wi-Fi is undeniable. Whether you’re grabbing a coffee, studying, or hanging out, connecting to a cafe’s complimentary internet seems like a no-brainer. It’s convenient, saves your mobile data, and keeps you connected without a second thought. From bustling city centers to quiet spots, public Wi-Fi has become an expected amenity, integral to our daily routines. But beneath this convenience lies a critical question: how secure is that "free" connection, really?

Globally, public Wi-Fi networks in airports, malls, and cafes often operate with minimal security. [I] Unlike your secure home network, these hotspots are typically unencrypted, meaning data traveling between your device and the internet is an open book. [II] Without strong protection, hackers can easily intercept your information, turning a simple browsing session into a potential data breach, exposing passwords and financial details. [III]

[IV] In Vietnam, this scenario plays out daily for millions. Popular chains like Highlands Coffee and The Coffee House, staples for many, provide readily available free Wi-Fi. As a 14 or 15-year-old, you likely use these networks at your favorite milk tea shop or cafe to scroll through TikTok or chat with friends, all while saving mobile data. This seemingly smart way to save data often masks a significant cybersecurity blind spot, making your digital presence more vulnerable.

Unsecured public Wi-Fi poses real and varied dangers. Malicious actors can set up fake Wi-Fi hotspots, tricking you into connecting to their rogue network. Once connected, they can launch "Man-in-the-Middle" attacks, eavesdropping on your online activities, stealing login credentials, or even injecting malware. For teens, this means social media accounts, gaming profiles, and personal photos could be compromised, leading to identity theft or online harassment. Your online interactions can quickly become a hacker's goldmine.

Protecting yourself requires vigilance. Always use a Virtual Private Network (VPN) on public Wi-Fi, as it encrypts your data. Avoid accessing sensitive information like online banking or shopping while connected to unsecured networks. Double-check the Wi-Fi network name, and disable automatic Wi-Fi connection on your devices. Your digital privacy is a valuable asset, especially for social media and personal information. Prioritizing security over convenience is a small step that offers huge protection in today’s interconnected world.