Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-37

The world’s oceans are constantly in motion, not just on the surface but also in their depths. These massive movements of water, known as ocean currents, act like giant rivers flowing through the sea. These movements (35) __________ mainly by two key forces: wind and differences in water density.

Surface currents, which affect the top 400 meters of the ocean, are (36) __________ caused by the wind blowing across the water’s surface. As the wind blows, it pushes the water, creating a flow. The friction between the wind and the water results (37) __________ the water moving in the same direction as the wind, transferring enormous amounts of energy.

Deep ocean currents, (38) __________, are not controlled by wind but by changes in water density. Density is influenced by both temperature and salinity (the amount of salt in the water). Water that is colder or has a higher salt content is (39) __________ denser than warmer, less salty water. This difference in density has a significant (40) __________ on how water moves in the deep ocean, as the denser water sinks below the less dense water.

This process creates a massive, slow-moving circulation system, often called the 'global conveyor belt', (41) __________ transports water around the entire planet. Cold, salty, dense water sinks in the polar regions and travels along the ocean floor. Eventually, it rises back to the surface in warmer areas, where it is warmed by the sun before circulating again.

In summary, ocean currents (42) __________ a vital role in distributing heat and nutrients around the world, influencing weather patterns and supporting marine ecosystems. Understanding the forces of wind, temperature, and salinity is key to understanding this essential global system. Both surface and deep currents are critical components of Earth's climate.

From the stylish sneakers on your feet to the classic bag you carry, leather is a dominant material in the fashion world. However, traditional leather production has a significant environmental footprint, requiring vast amounts of land and water, and raises ethical questions about animal welfare. As consumers, especially young people, become more aware of these issues, a groundbreaking solution is emerging from the world of biotechnology: lab-grown leather.

So, what exactly is this futuristic material? Instead of coming from animals, bio-leather is created in a laboratory using microorganisms. Scientists use cells from sources like mushroom roots (mycelium) or yeast, which are placed in a nutrient-rich liquid. In this controlled environment, the cells multiply and form a sheet-like material. These sheets are then cultivated and processed to mimic the texture and strength of conventional leather. The entire process represents a significant shift from traditional farming to cellular agriculture.

The advantages of this new bio-leather are compelling. The most obvious is the ethical benefit: no animals are harmed. Environmentally, the process promises to use far less water, land, and fewer harsh chemicals than traditional tanning. This new bio-leather is also incredibly versatile. It can be engineered to have specific qualities, such as extra durability, water resistance, or even different colors and textures, offering designers new creative possibilities.

Despite its promise, lab-grown leather faces several hurdles before it can become mainstream. The primary challenge is the high cost of production, which makes the final products more expensive than their traditional counterparts. Scaling up the technology from small lab batches to large, factory-level production is another significant obstacle. Finally, there's the question of consumer acceptance: will people be willing to embrace a material grown in a lab for their high-fashion items?

This global trend is particularly relevant for countries like Vietnam, which has a large and well-established leather and footwear industry. While this sector currently relies heavily on traditional animal leather, local innovators and fashion brands are watching the development of bio-leather closely. They see it as a potential pathway to more sustainable production in the future, allowing them to compete in an increasingly eco-conscious global market.

In conclusion, lab-grown leather stands at the intersection of fashion, technology, and sustainability. While challenges in cost and scale remain, its potential to offer a stylish, high-performance, and animal-friendly alternative is undeniable. For the next generation of consumers, it represents a future where your favorite accessories can be both chic and conscious.