Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-64

Everyone (35) __________ that we yawn when we feel tired or bored. We often see it as a simple sign of sleepiness. However, scientists are discovering the real reason is more complex. While tiredness can trigger a yawn, it's not the main cause. Yawning is a vital bodily process that helps regulate our most important organ.

The leading theory suggests we yawn to cool down our brains. When the brain becomes too (36) __________, it doesn't function as efficiently. A yawn acts like the body's natural air-conditioning system. This process is crucial (37) __________ maintaining optimal brain temperature and performance. If our brain overheats, our mental alertness can suffer.

The primary (38) __________ of a yawn is to increase blood flow to the brain. When you yawn, you stretch your jaw muscles. This action sends more blood to your head. (39) __________, the deep breath taken during a yawn brings cooler air into the body, which then cools the blood before it goes to the brain.

But why is yawning contagious? (40) __________ research suggests this is related to empathy. We yawn when we see others do it because we are subconsciously connecting with them. People (41) __________ are more empathetic tend to 'catch' yawns more easily. This behavior plays a crucial (42) __________ in our social interactions.

So, the next time you yawn, remember it might not be because you are bored. Your brain is likely just trying to cool down to help you focus. Yawning is a fascinating and essential function, showing there's often a surprising scientific reason behind our common behaviors.

In the heart of bustling cities, where skyscrapers touch the clouds and streets are filled with the constant hum of traffic, a quiet revolution is taking root. This revolution isn't fought with weapons, but with seeds and soil. Urban agriculture, particularly the development of rooftop gardens, is transforming unused spaces into productive green oases. As our world becomes more urbanized, these high-rise farms offer a creative solution to some of modern life's most pressing challenges, connecting city dwellers back to the source of their food.

The benefits of rooftop farming are numerous. Environmentally, they significantly reduce 'food miles'—the distance food travels from farm to plate. This reduction in transportation directly lowers the carbon footprint of our food supply. Health-wise, urban gardens provide access to incredibly fresh, nutrient-rich produce that is often grown without harmful pesticides. Furthermore, these green spaces act as the lungs of the city, improving air quality by absorbing carbon dioxide. For many urbanites, the opportunity to cultivate their own food provides a deep sense of satisfaction and a stronger connection to nature.

However, establishing a rooftop garden is not without its difficulties. A primary concern is structural integrity; not all buildings are strong enough to support the weight of soil, water, and plants. The initial setup costs for equipment, soil, and irrigation systems can also be a significant barrier for individuals or communities. Moreover, successful gardening requires knowledge and a consistent commitment of time and effort, which can be challenging for people with busy urban lifestyles. Fortunately, innovative solutions are emerging. Companies in Vietnam, like V-Space, are promoting hydroponic systems which are lighter, soil-less, and often more manageable for urban settings.

In major Vietnamese cities like Da Nang and Ho Chi Minh City, the rooftop gardening movement is gaining impressive momentum. It's not just about individual balconies; it’s about creating shared community gardens where neighbors can work together. These projects do more than just produce vegetables; they foster a sense of community, collaboration, and shared purpose among residents. By sharing the workload and costs, these community gardens make urban farming more accessible and enjoyable for everyone involved, turning sterile rooftops into vibrant social hubs.

Looking ahead, rooftop gardens are more than just a passing trend. They represent a fundamental shift in how we think about food, community, and urban living. While they may not replace traditional agriculture entirely, they are a vital step towards creating more sustainable, self-sufficient, and resilient cities. For the next generation, learning to grow food in the middle of a concrete jungle could be one of the most important skills for a healthier and greener future.