Đề ôn thi Đề thi vào lớp 10 Trường Phổ thông Năng khiếu môn Tiếng Anh - Mã đề PTNK-144

Have you ever noticed the 'L' and 'R' letters on your headphones? These symbols are not just for decoration; they indicate the left and right audio channels. Each channel plays a slightly different audio track, which is a key feature of stereo sound. The purpose is to send (21) __________ audio information to each of your ears, just like you hear sounds in the real world from different directions.

This system is called stereophonic sound, or 'stereo' for short. By playing different sounds in each ear, audio engineers can create a sense of direction and space. So that your brain (22) __________ process these differences, the soundscape feels wider and more three-dimensional. A stereo recording is almost always more immersive than a mono recording, where the exact same sound is sent to both ears.

Our brains are naturally skilled at identifying where sounds come from. (23) __________ is because our two ears hear sounds at slightly different times and volumes depending on their source. Stereo technology uses this principle to replicate an experience that feels natural. For example, a sound that is louder in the right channel will seem to come from your right side.

This technology greatly improves the listening experience. When you listen to music, you might hear the guitar primarily in your left ear and the piano in your right, making the mix feel more spacious and (24) __________. In movies, it allows for sound effects to move from one side to the other, following the action on screen. Not only does this make media more engaging, but it is also essential for applications like gaming, where knowing the direction of a sound is crucial.

In conclusion, the 'L' and 'R' on your headphones are fundamental to creating a rich and convincing audio world. They enable stereo sound, which works with your brain's natural abilities to simulate a realistic, three-dimensional soundscape. The next time you put on your headphones, pay attention to the different sounds in each ear and appreciate the clever technology at work.

National parks globally face the challenge of balancing conservation with tourism. These vital sanctuaries preserve diverse ecosystems and endangered species, often housing unique geological formations. However, they perpetually grapple with a fundamental dilemma: how to allow public access while safeguarding their delicate environments. In Vietnam, Cúc Phương National Park, established in 1962, exemplifies this very challenge. As the country's first national park, this sprawling expanse of ancient rainforest is both a scientific treasure and an increasingly popular destination, prompting questions about its core purpose and our role within it. [I]

Cúc Phương is renowned for its exceptional biodiversity, housing thousands of species, many of which are endemic or critically endangered. Its unique limestone karst mountains nurture a complex web of life, from rare plants to fascinating insects and mammals. A celebrated conservation effort within the park is the Endangered Primate Rescue Center, a dedicated facility working tirelessly to rehabilitate and reintroduce rare and threatened primates, such as the Delacour's langur. This center underscores the park's indispensable role as a scientific research hub and a safe haven, truly embodying its identity as a treasure to protect for future generations. [II]

[III] Visitors can explore ancient trees, discover stunning caves, and observe exotic birdlife. The educational value of such visits is undeniable; these trips offer a unique opportunity to connect with nature, learn about environmental conservation, and witness the incredible efforts being made to protect vulnerable species firsthand. For many, a visit to Cúc Phương is an immersive experience, fostering a deeper appreciation for Vietnam’s natural beauty.

However, Cúc Phương's increasing popularity brings significant management challenges. A surge in tourist numbers, if unchecked, can lead to environmental degradation, including habitat disturbance, littering, and noise pollution, directly impacting its delicate ecosystem. The very act of visiting, though educational, can stress the park’s resources and wildlife. Authorities strive for sustainable tourism, implementing designated pathways, strict waste management, and visitor education programs, all aimed at minimizing human footprint while still allowing access to its wonders. [IV]

This brings us to the central question: Is Cúc Phương National Park primarily a treasure to protect, or a place designed for us to visit? In truth, it is both, but the balance is precarious and requires thoughtful engagement from every visitor. As young visitors experiencing these natural wonders, understanding our role is paramount. We are not just spectators; we are temporary custodians. By following park rules, respecting wildlife, and supporting eco-friendly initiatives, we ensure Cúc Phương remains both a vital sanctuary for its incredible biodiversity and an inspiring destination for generations to come.