Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-109

Concrete is one of the most common building materials in the world. It is made by mixing cement, water, sand, and gravel. When it hardens, concrete is incredibly (35) __________ under compression, which is the force of being pushed together. However, it has a significant weakness. It is quite brittle and (36) __________ easily crack or break when pulled apart, a force known as tension.

To solve this problem, engineers use steel. Steel is an alloy known for its impressive tensile strength. This means it is very strong when being pulled or stretched. Unlike brittle concrete, steel is (37) __________, allowing it to bend slightly without breaking. This property makes it the perfect partner for concrete.

The solution is to combine the two materials to create reinforced concrete. Engineers place steel bars, often called rebar, inside the formwork before the liquid concrete is poured. (38) __________ allows the steel to be perfectly embedded within the concrete as it hardens. The result is a composite material that is much (39) __________ and more reliable than concrete alone.

This combination is brilliantly effective. The concrete component resists the compressive forces from the structure's weight. Meanwhile, the embedded steel bars (40) __________ any tensile forces, such as those caused by wind or earthquakes. Seldom (41) __________ a single material offer such a complete solution, but the synergy between these two does.

(42) __________, the invention of reinforced concrete revolutionized construction. It allows us to build everything from towering skyscrapers and long bridges to simple homes and foundations. Its strength, durability, and versatility have made it perhaps the most important building material of the modern age.

Cities around the world are growing rapidly, but this growth often comes with problems like pollution, traffic jams, and a lack of green space. In response, architects and urban planners are developing an exciting concept: the eco-city. An eco-city is a city designed to be in balance with nature, aiming to minimize its environmental impact and improve the quality of life for its residents. This is not just a distant dream; countries like Vietnam are actively exploring and implementing these futuristic ideas to build healthier communities.

A key element of an eco-city is its green infrastructure. This involves more than just planting a few trees. Imagine buildings covered in vertical gardens, which help cool the air and improve biodiversity. Rooftops would be fitted with solar panels to generate clean, renewable energy. The entire city would be designed with sustainable architecture, using recycled materials and energy-efficient systems. Green corridors—strips of parkland and waterways—would connect different neighborhoods, allowing wildlife to thrive and giving people beautiful spaces for recreation.

Technology also plays a crucial role. Smart public transport systems are at the heart of an eco-city’s mobility plan. Instead of relying on private cars, residents would use a network of efficient electric buses, trams, and extensive bike-sharing programs. This significantly reduces carbon emissions and traffic congestion. Furthermore, eco-cities would feature smart waste management systems, where sensors in bins signal when they are full, and automated systems sort waste for recycling, turning trash into a valuable resource.

In Vietnam, this vision is already taking shape. The Ecopark urban area near Hanoi is a prominent example of a large-scale development focused on green living. With over 100 hectares of trees and water, it prioritizes natural landscapes over concrete. These developments are not just created for their aesthetic appeal. They are fundamentally designed to promote a healthier lifestyle, reduce stress, and create a stronger sense of community among residents. The success of projects like Ecopark shows a strong commitment to a greener urban future in the country.

For teenagers today, these concepts are particularly relevant. The cities you will live, work, and raise families in are being planned right now. Understanding the principles of eco-cities allows you to be part of the conversation about your own future. By supporting sustainable initiatives and adopting greener habits, you can help ensure that the cities of tomorrow in Vietnam are not just smart, but also truly wise and in harmony with the planet.