Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-139

Wind power is (35) __________ important source of renewable energy, offering a clean alternative to fossil fuels. Many countries are investing heavily in it as a way to combat climate change. However, while it has many benefits, using wind power also comes with several significant challenges that must be addressed for it to be a truly reliable energy source for the future.

The primary challenge is its intermittency. The wind does not always blow, and its speed can vary greatly. This means that the power supply can be very (36) __________. If the wind speed were consistently ideal, wind power (37) __________ a much more reliable energy source. Because of this variability, power grids cannot entirely (38) __________ wind energy alone and must have backup power sources available.

Another disadvantage is related to land use and location. Wind farms require a lot of space, often in rural or coastal areas where the wind is strongest. (39) __________, finding a suitable location can be a major issue, as it can conflict with agriculture, wildlife habitats, or scenic landscapes. The best locations are often far from cities, which means expensive new power lines must be built.

Furthermore, the operation of wind turbines can be problematic. Some people who live near wind farms complain about the noise. One resident said that the turbines (40) __________ like a jet engine when the wind was strong. There is also the visual impact; some feel that large fields of turbines spoil the natural beauty of the countryside. The initial investment for wind farms is significant, and building them can (41) __________.

Overcoming these issues is key to expanding wind energy. Scientists are working on better ways to predict wind patterns and improve turbine efficiency. One potential solution involves (42) __________ excess energy in large batteries for use when the wind isn't blowing. By tackling these challenges, we can make better use of this powerful, clean resource.

The clock strikes midnight, but for many students across Vietnam, the night is far from over. With a major exam just hours away, the temptation to 'pull an all-nighter' is strong. Textbooks are open, coffee is brewing, and the belief is that more hours studying equals a better grade. But what if this common strategy is not just ineffective, but actually harmful to academic performance? This question is becoming increasingly important as students face growing academic pressure.

The answer lies in the science of sleep. While we are unconscious, our brains are hard at work. This process, known as memory consolidation, is when the brain sorts, processes, and stores the information we learned during the day. During different sleep stages, especially REM (Rapid Eye Movement) sleep, neural connections are strengthened, turning short-term memories into long-term knowledge. Without adequate sleep, this crucial transfer cannot happen effectively. It's like gathering ingredients for a meal but never actually cooking it; the information is there, but it isn't ready to be used.

The consequences of skipping sleep extend beyond poor memory. Sleep deprivation directly impairs cognitive functions. A tired brain struggles with focus, making it difficult to concentrate during an exam. Problem-solving abilities are reduced, and creative thinking becomes nearly impossible. Furthermore, a lack of sleep increases the production of stress hormones, leading to anxiety and a negative mood. So, even if you manage to read every page of your textbook, your exhausted brain may not be able to recall or apply the information when it matters most. These effects can also impact physical health and emotional well-being.

This issue has gained significant attention in Vietnam. Health experts have raised concerns that students are not getting the recommended 8 to 10 hours of sleep per night due to heavy homework loads and early school start times. In response, city authorities, such as those in Ho Chi Minh City, have begun discussing and implementing regulations to adjust school schedules. These new policies aim to provide students with a better opportunity to get sufficient rest. They are a clear recognition from officials that quality sleep is a vital component of a student's education and overall health.

Ultimately, the evidence is clear: sacrificing sleep for extra study time is a counterproductive strategy. A more effective approach involves smart time management. Creating a consistent study schedule, breaking down material into smaller chunks, and reviewing regularly are far more beneficial than a single, frantic, overnight session. To improve sleep quality, students should also avoid caffeine late in the evening and create a relaxing bedtime routine. Prioritizing sleep is not a sign of weakness; it is one of the smartest decisions a student can make for academic success.