Đề ôn thi Đề thi vào lớp 10 Trường Phổ thông Năng khiếu môn Tiếng Anh - Mã đề PTNK-95

Inside almost every cell of every living thing, there is a special molecule known as deoxyribonucleic acid, or DNA. It is a molecule that (21) __________ all of the body's instructions for building and maintaining an organism. Think of it as a detailed blueprint or a recipe book for life. These instructions determine everything from the color of your eyes to how your body fights illnesses. Every person's DNA is unique, which is why we are all different.

The structure of DNA is one of the most famous scientific images in the world. It is called a double helix, which looks like a twisted ladder. The two long sides of the ladder are made of sugar and phosphate molecules, and the rungs connecting them are made of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). This structure is incredibly compact and stable, allowing a huge amount of information to be stored in a very small space. This is crucial for the cell's ability to copy and pass on genetic information accurately.

The information in DNA is written in a special code using the four chemical bases. The sequence of these bases forms specific segments of DNA called genes. Each gene carries the instructions for one specific function or trait. For a cell to operate (22) __________, it must read these genes correctly and follow their instructions precisely. The entire set of these instructions in an organism is called its genome.

Because of its unique nature, DNA (23) __________ be used for many practical purposes, such as identifying individuals in criminal investigations or establishing family relationships. Scientists constantly conduct research to better understand the genome and how different genes work. Rarely does an error in the DNA code lead to a positive outcome; most often, such mistakes cause problems or diseases. This highlights the importance of the DNA's stability.

(24) __________, DNA is the fundamental molecule of life. It carries the unique genetic code that makes each organism what it is, provides the instructions for cellular functions, and allows genetic information to be passed from one generation to the next. Its discovery and ongoing study continue to revolutionize biology and medicine.

Travel offers incredible experiences, and we seek tangible reminders. Souvenirs serve this purpose, small tokens evoking the sights, sounds, and feelings of a journey. For a long time, the market was dominated by mass-produced items, often lacking genuine connection to their place. [I] Travellers are increasingly looking beyond generic trinkets, seeking authentic pieces that tell a story and reflect a destination’s true essence. [II] This awareness is transforming souvenir purchases.

So, what truly makes a good souvenir? It’s more than just an object; it’s a fragment of the place itself, infused with local spirit. The best souvenirs are often handcrafted, unique, and directly support the communities you visit. They carry a narrative – about its artisan, traditional techniques, or local materials. This emphasis on authenticity transforms a simple purchase into a meaningful act, forging a deeper bond with the culture and memory of your trip. [III]

Vietnam, for instance, exemplifies meaningful tourism. The Vietnamese government actively champions its rich heritage of traditional craft villages. Places like Bat Trang pottery village, near Hanoi, are living workshops where visitors witness the creation process firsthand. Here, you can purchase crafted pottery directly from skilled artisans, not from a factory. This direct interaction ensures authenticity and provides vital support for centuries-old artistic traditions, preserving them.

For young travellers, this choice holds particular significance. When you pick out a souvenir for yourself or a gift, it's a conscious decision. Opting for an item made by a local artist or a community cooperative means your money directly benefits individuals and the local economy. It's a powerful way to vote with your wallet, preserving cultural integrity and supporting ethical production over distant manufacturing. [IV] This simple act turns your souvenir into a symbol of responsible travel.

Ultimately, a souvenir’s value isn't its price, but the story it carries and its positive impact. A truly good souvenir is a piece of art, a fragment of culture, and a tangible reminder of a unique experience. It’s a conversation starter and a testament to the choices we make as global citizens. By choosing thoughtfully, you bring home more than just an object; you bring home a memory infused with meaning, a piece of someone’s heart, contributing to a better world.