Đề ôn thi Đề thi vào lớp 10 Trường Phổ thông Năng khiếu môn Tiếng Anh - Mã đề PTNK-86

Have you ever wondered why our year has 365 days, but a year on another planet might be much shorter or longer? The answer lies in basic celestial mechanics. A planet's 'year' is the time it takes to complete one full journey, or revolution, around its star. This period is determined by the planet's orbit—the path it follows through space. Each planet in our solar system travels around the Sun, but not all of them take the same amount of time to finish their trip.

Let's take our home, Earth. Its orbit around the Sun is a very long journey. The time it takes for Earth to travel this entire path is approximately 365.25 days. (21) __________ is what we define as one Earth year and why we add a leap day to our calendar every four years. This concept of a year is entirely based on our planet's movement through space, a fundamental cycle of time for us.

Now, consider other planets. Mercury, the planet closest to the Sun, has a much smaller orbit. Because its path is shorter, its year is only 88 Earth days long. In contrast, Mars is farther from the Sun than Earth is. Consequently, Mars's orbit is larger, and it has a (22) __________ journey to make. A year on Mars is much longer, lasting about 687 Earth days, which is almost twice as long as Earth's year.

Not only does the orbital path get larger for distant planets, but their travel speed also decreases. They move more slowly due to the star's weaker gravitational pull. Therefore, they have to (23) __________ a greater distance at a slower speed. For this reason, we must conclude that a planet's distance from its star is the most important factor that influences the length of its year.

(24) __________, the length of a 'year' is unique to each planet because of its position. The specific path a planet follows around its star, called an orbit, and the speed at which it travels, both depend on this position. From the swift 88-day year of Mercury to the nearly two-year-long journey of Mars, each planet's calendar is a unique result of its place in the solar system.

Imagine a sprawling city, a "concrete jungle" where skyscrapers dominate the horizon. Farming seems an unlikely activity here, yet a quiet revolution is taking root high above: rooftop gardens. This innovative urban agriculture trend gains global momentum, transforming unused spaces into vibrant food production zones. The push for local, fresh produce and a significant reduction in environmental impact from food transportation makes these elevated green spaces vital. Rooftop gardens offer a compelling vision for how cities can become more self-sufficient and eco-friendly. [I]

Rooftop gardens are more than just aesthetic additions; they are practical urban solutions. [II] By repurposing the vast surfaces of building roofs, they bring food production closer to consumers, drastically cutting "food miles." Beyond fresh produce, these green havens also improve air quality by absorbing pollutants and releasing oxygen. [III] Furthermore, these elevated ecosystems foster urban biodiversity, providing habitats for insects and birds, turning grey areas green in the most unexpected places.

This global trend strongly resonates in Vietnam's rapidly developing urban centers. Cities like Da Nang and Ho Chi Minh City, with their dense populations, show a growing interest in urban farming. Community projects encourage residents to grow food even in compact spaces. Companies such as V-Space actively promote and install modern hydroponic and rooftop gardening systems, making this practice more accessible. [IV] These local efforts demonstrate proactive environmental stewardship and food security, tailoring innovative solutions for Vietnamese cities.

For a 14 or 15-year-old living in a bustling city, a rooftop garden might sound futuristic, but it's becoming real. Imagine walking a few steps from your apartment to harvest fresh, organic vegetables for dinner, knowing exactly where your food came from. This explores a cool, practical way for city dwellers to connect with nature, understand food systems, and contribute to their community. It’s a hands-on experience sparking curiosity about botany, sustainability, and healthy eating, proving you don't need vast land to grow your own food.

Ultimately, rooftop gardens symbolize urban innovation and resilience. They challenge the traditional notion that farming belongs only to rural areas, demonstrating that cities can and must integrate food production into their fabric. As urban populations continue to grow, these elevated farms will play an increasingly critical role in ensuring food security, enhancing environmental quality, and fostering stronger community ties. The future of farming might just be found not on vast plains, but nestled atop high-rises, transforming our cities into greener, healthier, more sustainable places for all.