Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-154

Steel is one of the most important industrial materials in the world, used in everything from skyscrapers to cutlery. But how is this strong and versatile metal created? The journey begins with a raw material called iron ore, and the entire transformation process is quite fascinating. Fundamentally, steel (35) __________ by adding carbon to iron.

The first major step is heating the iron ore in a special, massive oven called a blast furnace, (36) __________ temperatures can reach over 1,500 degrees Celsius. This intense heat melts the iron ore, separating the iron from other natural materials. The result of this stage is a hot, liquid iron, which is the base ingredient for making steel.

Once the liquid iron is ready, it is mixed (37) __________ a carefully measured amount of carbon. This is the most critical part of the process, as it is the carbon that turns iron into steel, creating a new material known as an alloy. The amount of carbon added is (38) __________ because it determines how hard and strong the final steel will be.

(39) __________, other elements are sometimes added to give the steel special properties, such as resistance to rust. A crucial step is to (40) __________ impurities from the molten metal. (41) __________ these unwanted substances, like sulfur and phosphorus, must be cleared away as they can weaken the final product.

This final cleaning step has a significant (42) __________ on the steel's properties, ensuring it is much stronger and more durable than pure iron. Because of this enhanced strength and versatility, steel remains a cornerstone of modern construction and manufacturing.

For many teenagers, the thought of a first big trip, perhaps with friends or family, is incredibly exciting. The question that often arises is how to travel. Should you join a guided tour, where every detail is planned for you, or venture out independently? In countries like Vietnam, package tours from companies like The Sinh Tourist are popular, offering a convenient way to see highlights from Hanoi to Ho Chi Minh City. They present a clear choice: the structured comfort of a tour versus the unpredictable adventure of solo travel.

The primary advantage of a guided tour is convenience. Imagine a trip where you don't have to worry about booking hotels, finding reputable bus companies, or queuing for tickets to famous landmarks. Tour companies handle all these logistics, providing a relatively hassle-free experience. This is especially valuable for first-time visitors who may feel overwhelmed by a new culture and language. Furthermore, tours are efficient. A well-designed itinerary ensures you see the most important sights in a limited amount of time, with a guide who provides historical context and interesting facts that you might otherwise miss.

However, this convenience comes at a cost, and that cost is freedom. Guided tours operate on a strict schedule. You might find a charming café or a fascinating market, but there's no time to explore it because the tour bus leaves in ten minutes. This structured approach ensures you see the main attractions, but it often prevents a deeper, more personal connection with the place. You are always part of a group, which means less opportunity for spontaneous conversations with locals and a more superficial understanding of the daily life and culture.

On the other hand, independent travel offers complete autonomy. You decide when to wake up, where to eat, and how long to spend at a museum. This flexibility allows for unplanned discoveries—the hidden alleyway with the best phở, a conversation with a local artist, or an impromptu decision to stay an extra day in a city you love. Navigating a new place on your own also builds valuable life skills, such as problem-solving, budgeting, and self-reliance. It forces you to engage directly with the local environment, fostering a more authentic and memorable experience.

Ultimately, there is no single 'best' way to travel. The ideal choice depends entirely on the traveler's personality, experience level, and what they hope to gain from their journey. A nervous first-time traveler might find comfort and security in a guided tour, while a seasoned adventurer might crave the freedom and challenge of independent exploration. The key is to understand the trade-offs between convenience and freedom, and to choose the path that best suits your own travel dreams.