Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-126

Tower cranes are a common sight in any city with new construction projects. They are the tall machines that stand over new buildings, looking like giant metal birds. Their primary job is the vertical (35) __________ of heavy materials, such as steel beams and concrete blocks, from the ground to the upper floors of a structure. Without them, building skyscrapers would be nearly impossible.

The crane has several key parts. The most noticeable is the mast, which is the vertical tower that gives the crane its height. As the building gets taller, new sections are added to the mast, allowing the crane to grow with it. (36) __________ process is fascinating, as the crane essentially builds itself higher using a special climbing frame.

On top of the mast sits the slewing unit, which allows the machine to rotate. Extending from this unit is the long horizontal arm called the jib. This is the part that carries the load. At the other end, there are large concrete counterweights. These are crucial for balance. Without these heavy blocks, the crane (37) __________ simply tip over when lifting a heavy load. The operator must (38) __________ careful attention to the weight limits.

Of all the machinery on a modern construction site, the tower crane is often the (39) __________. Its great height and long reach make it an incredibly efficient tool. The operator, who sits in a small cab at the top of the mast, has a unique view of the entire project. Not only (40) __________ they need excellent coordination, but they also require a deep understanding of physics and safety procedures.

(41) __________, the tower crane is more than just a machine; it is a symbol of urban growth and engineering achievement. Its ability to lift incredible weights to great heights with precision is what makes the construction of today's impressive city skylines possible. They are truly (42) __________ tools for any major building project.

Anyone living in a hot, humid climate like Vietnam's understands the daily struggle to stay cool and comfortable. For generations, the go-to solutions have been lightweight, natural fabrics like cotton and linen. While these materials are breathable, they often absorb sweat and become heavy and damp, sticking uncomfortably to the skin. But what if our clothes could do more than just cover us? What if they could actively help us cool down? This is no longer science fiction; it's the cutting edge of material science.

Scientists are developing innovative fabrics engineered with specific cooling properties. One of the most promising approaches is 'radiative cooling'. All objects, including our bodies, release heat in the form of infrared radiation. Traditional fabrics trap this heat close to the skin. Radiative cooling textiles, however, are designed to be transparent to this infrared radiation, allowing body heat to escape directly into the environment. Another popular technology is advanced moisture-wicking. Unlike cotton which simply absorbs moisture, these synthetic fabrics pull sweat away from the skin to the outer surface of the garment, where it can evaporate quickly. This process of evaporation is what creates a powerful cooling sensation.

Creating these high-tech textiles involves sophisticated engineering. For instance, some radiative cooling fabrics are made from nano-porous polyethylene—a material similar to plastic wrap but filled with microscopic pores that let heat out while blocking visible light. Other fabrics might have their fibers coated with special nanoparticles. They are often more expensive to produce than traditional textiles and face challenges in matching the soft, natural feel of cotton. However, as research progresses, scientists are finding ways to improve their texture and reduce production costs, making them more practical for everyday use.

This wave of innovation is particularly relevant for Vietnam's booming textile industry. To compete on the global stage, many local companies are shifting their focus from mass production to creating high-value products with advanced features. We can already see this trend in the local market. Brands like Coolmate have gained immense popularity among young Vietnamese consumers by focusing specifically on technology-enhanced basics, such as t-shirts and underwear made from moisture-wicking materials. Their success proves there is a strong demand for clothing that offers a scientific solution to the discomfort of a tropical climate.

The development of cooling fabrics represents a significant leap forward in how we think about clothing. No longer just a matter of fashion or modesty, our garments are becoming functional tools to enhance our daily comfort and well-being. As these technologies become more widespread and affordable, the sweaty, sticky feeling of a hot day could soon become a thing of the past.