Đề ôn thi Đề thi vào lớp 10 Trường Phổ thông Năng khiếu môn Tiếng Anh - Mã đề PTNK-01

The Global Positioning System, or GPS, is a remarkable technology that many of us use every day without a second thought. It is a satellite-based navigation system that provides location and time information anywhere on or near the Earth. This system is made up of a network of satellites orbiting our planet and the GPS receivers in our devices, like smartphones or car navigation units. Its primary function is to help a receiver determine its exact position.

The first part of the system is the satellite network. There are more than twenty-four GPS satellites orbiting the Earth at a very high altitude. Signals are sent constantly from these satellites down to the surface. Each signal travels at the speed of light and contains information about the satellite's position and the exact time the signal was transmitted. This timekeeping is incredibly accurate, thanks to the atomic clocks on board each satellite.

The second part is your GPS receiver. The receiver's main job is to listen for these signals. It needs to pick up signals from multiple satellites to work properly. The receiver, (21) __________ is often built into your phone, detects these signals and uses the information within them. The data contains precise timing information that is crucial for the next step of the process. It is a passive device, meaning it only receives signals and does not send them.

The calculation of your location is based on a principle called trilateration. To calculate a 2D position, which includes latitude and longitude, signals from at least three satellites are needed. The receiver measures the time it takes for a signal to travel from a satellite to the device. (22) __________, for a more accurate 3D position that includes altitude, a fourth satellite is required. This information helps to calculate the (23) __________ to each satellite, which is a key part of finding your location.

Once the receiver has the distances from four or more satellites, it can calculate its exact position in a fraction of a second. This location is then shown on your device's map application. The entire process is continuous, allowing for real-time tracking of your movement. (24) __________ person with a modern smartphone can benefit from this amazing technology, whether for finding a new restaurant or navigating through an unfamiliar city.

Embarking on a journey to a new country can be exhilarating yet daunting. For many travelers, particularly first-timers, planning everything—from flights and accommodation to sightseeing—feels overwhelming. This is where package group tours step in. [I] While they promise convenience, a key question arises: are guided tours the easy way to travel, or do they sacrifice too much freedom?

The primary appeal of a group tour lies in its effortless nature. Travelers can relax, knowing every detail has been handled, eliminating the stress of navigation or unforeseen logistical issues. For those venturing into unfamiliar territory, the security of traveling with an experienced guide and a group is reassuring. [II] Such tours are highly efficient, often packing many landmarks and experiences into a condensed timeframe, ideal for visitors with limited time but a strong desire to see highlights without personal planning.

Organized travel thrives in places like Vietnam, where companies have perfected convenient, affordable tours. Firms like The Sinh Tourist (formerly Sinh Cafe) are renowned for bus tours linking iconic destinations: from Hanoi's bustling streets to Ha Long Bay's serene waters and Hoi An's ancient charm. [III] These services cater to a wide range of tourists, including budget-conscious backpackers, providing a hassle-free way to explore the country’s diverse landscapes and culture without extensive personal planning.

Yet, this convenience comes at a cost – reduced personal freedom. Group tours operate on a fixed schedule, meaning little room for spontaneity or lingering. Participants are often moving from one attraction to the next, adhering to a strict timeline. [IV] The opportunity to discover hidden local gems, enjoy leisurely meals, or simply spend an afternoon people-watching is often sacrificed. For those who cherish independent exploration and enjoy forging their own path, the structured nature of a guided tour can feel restrictive, even stifling.

So, for a 14 or 15-year-old considering their first big trip, perhaps with school friends or family, the choice between a guided tour and independent travel requires careful thought. On one hand, a tour guarantees ease and access to major sights, ensuring a smooth experience. On the other, it limits the adventurous spirit and the chance for unique, unplanned discoveries that often define memorable trips. Ultimately, the best option hinges on personal travel style: is the priority effortless efficiency and security, or the exhilarating freedom to explore the world on your own terms?