Đề ôn thi Đề thi vào lớp 10 Trường Phổ thông Năng khiếu môn Tiếng Anh - Mã đề PTNK-77

Coral reefs are among the most diverse ecosystems on Earth. Often called the "rainforests of the sea," these underwater structures are built by tiny organisms. A coral reef is a complex community that supports an incredible variety of life, making it a vital part of the marine environment. The vibrant colors and bustling activity of a reef are a sign of its health and importance.

The fundamental structure of a reef is made up (21) __________ tiny animals called coral polyps. These polyps, (22) __________ are related to jellyfish, build hard, protective skeletons around themselves from calcium carbonate. Over thousands of years, the skeletons of millions of polyps grow together to form the massive structures that we recognize as coral reefs.

Inside their tissues, coral polyps host microscopic algae. This is a mutually beneficial relationship, known as symbiosis. The algae use sunlight to produce food, which they share with the coral, and in return, the coral provides a protected home for the algae. This partnership also gives corals their brilliant colors.

(23) __________ they cover less than 1% of the ocean floor, coral reefs support about 25% of all marine species. In these ecosystems, shelter is provided for countless marine creatures, from small fish and invertebrates to larger animals like sharks and sea turtles. The overall effect of this biodiversity is a healthy and balanced marine food web.

Many species of fish, crabs, and turtles depend on them for food and safety. For this reason, it is crucial that we understand the threats they face from pollution and climate change. We must take (24) __________ to protect these fragile and essential ecosystems for future generations.

Flash sales are a digital phenomenon, a whirlwind of excitement and incredible deals. If you've ever found yourself glued to your screen during a Tiki or Shopee 11/11 sale, eagerly anticipating a product's price drop, you've experienced the magic first-hand. But have you ever wondered about the intricate science behind these fleeting opportunities? It's more than simple discounts; these events are carefully orchestrated operations designed to capture your attention and, ultimately, your clicks. [I]

The allure of a flash sale lies deep within human psychology. Platforms expertly leverage principles like urgency and scarcity. Countdown timers prominently displayed aren't just for show; they trigger the "fear of missing out" (FOMO), compelling you to act quickly before a deal vanishes. Similarly, "only X left in stock" notifications create a competitive environment, making that item seem even more desirable. This combination transforms shopping into a thrilling race, often leading to impulse buys. [II]

[III] Major Vietnamese e-commerce players like Tiki and Shopee invest heavily to handle immense traffic spikes during peak sale periods. Millions of users simultaneously accessing products require robust servers and scalable cloud computing to prevent crashes. Moreover, algorithms personalize your shopping experience, displaying items you're more likely to buy based on your browsing history and previous purchases.

[IV] The "science" of a flash sale extends deeply into data analytics and artificial intelligence. Every click, every view, and every purchase you make contributes to a vast ocean of data. E-commerce platforms meticulously analyze this information to understand consumer behavior, predict demand, and even dynamically adjust prices in real-time. This allows them to strategically release limited-time offers almost guaranteed to resonate with specific user segments. It’s like having a digital salesperson who knows exactly what you want.

Understanding the blend of psychological triggers and advanced technology employed in flash sales can change how you perceive these events. Next time you're captivated by a fantastic deal on Tiki or Shopee, remember it’s a carefully crafted strategy. While the thrill of a good bargain is undeniable, being aware of these tactics empowers you to make more informed decisions, helping you distinguish between a genuine need and a cleverly engineered impulse.