Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-86

Many people enjoy listening to music or podcasts on the go, but unwanted background noise from traffic, crowds, or airplanes can ruin the experience. Noise-cancelling headphones offer a high-tech solution to this common problem. Unlike traditional headphones that simply use thick padding to block sound, these advanced devices use a clever process called Active Noise Cancellation (ANC) to create a zone of silence for the listener.

So, how do they achieve this? The magic begins with a process that is counter-intuitive. It works by first (35) __________ to the sounds around you using a tiny (36) __________ built into the earcups. This microphone's job is to detect the pattern of the external, unwanted sound waves before they reach your ears. The headphones are not just blocking noise; they are actively fighting it with more sound.

Once the microphone captures the outside noise, the headphone's internal electronics instantly analyze it. This tiny computer chip figures out the exact shape of the sound wave, including its frequency and amplitude. It then generates a brand new sound wave that is a perfect mirror image, or opposite, of the original one. This new wave is often called 'anti-noise'. This whole process happens in a fraction of a second.

(37) __________, when the original noise wave and the newly created anti-noise wave meet inside the headphone cup, they cancel each other out in a phenomenon known as destructive interference. This process effectively helps to (38) __________ constant background noise, leaving you with either silence or a much clearer audio experience. The result is that the annoying drone of a plane engine seems to disappear.

However, it is important to understand that not all noise can be removed. The technology is most effective against (39) __________ constant, low-frequency sound of a jet engine or air conditioner. A technology journalist once wrote that the science (40) __________ simple but the engineering was complex. (41) __________, these headphones create a personal bubble of quiet. If you (42) __________ to block out sudden noises like a dog barking, traditional earplugs might still be a better choice.

In the vast world of online content, some creators rise to prominence not through elaborate productions, but through pure passion and a desire to share their culture. Helen Le, the Vietnamese-Canadian creator behind the immensely popular YouTube channel 'Helen's Recipes,' is a prime example. Since starting her channel, her mission has been clear: to demystify Vietnamese cuisine and make it accessible for home cooks anywhere in the world, proving that anyone can create delicious, traditional meals in their own kitchen.

Helen’s journey began not in a professional culinary school, but from a personal need. Living in Canada, she deeply missed the flavors of her homeland, Vietnam. When she searched online for recipes to recreate her favorite dishes, she discovered a significant gap. While many recipes existed, they often lacked the clear, step-by-step instructions necessary for a beginner. She realized that many people were intimidated by Vietnamese cooking. This motivated her to start her own channel, focusing on providing easy-to-follow guides for authentic Vietnamese food.

The key to her channel’s success lies in her teaching style. Helen presents her recipes with a calm, encouraging demeanor that makes viewers feel capable and supported. She meticulously breaks down complex techniques into simple, manageable steps, and she often explains the cultural context behind a dish. These qualities have helped her build a loyal community of millions of followers who trust her guidance. Viewers are not just learning recipes; they are connecting with a culture and a friendly teacher who cheers for their success.

The influence of 'Helen's Recipes' has expanded far beyond YouTube. Recognizing the demand from her audience for a physical resource, Helen authored and published best-selling cookbooks. These books serve as tangible companions to her video library, allowing fans to have her trusted recipes on their kitchen counters. Furthermore, her status as a prominent voice in the culinary world has led to various collaborations and features, solidifying her role as an unofficial cultural ambassador for Vietnamese cuisine on the global stage.

Ultimately, Helen Le's story is a powerful illustration for today's teenagers. It demonstrates that a career path can be forged from a personal passion, using modern digital platforms to reach a global audience. Her success was not planned in a boardroom but grew organically from a genuine desire to solve a problem she faced herself. It’s a modern narrative of entrepreneurship, showing that with dedication and a unique voice, it is possible to turn what you love into a fulfilling and impactful career.