Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-02

For centuries, engineers (35) __________ simple machines to solve complex problems. One of the most basic yet effective of these is the inclined plane, which is simply a flat, supporting surface tilted at an angle, with one end higher than the other. The main purpose of an inclined plane is to help raise or lower an object by reducing the amount of force needed. It's a foundational tool in physics and engineering.

Imagine you need to lift a heavy box onto a truck. Lifting it straight up requires a great deal of force. (36) __________, if you use a ramp, you are essentially trading force for distance. You will have to push the box over a longer path, but the force you need to apply at any given moment is significantly less. This makes the task much easier to accomplish.

You can see inclined planes everywhere in daily life. Stairs are a type of inclined plane, allowing us to move (37) __________ to different floors with less effort than climbing a ladder. Another common example is a wheelchair ramp, a simple structure (38) __________ provides access to buildings for people with mobility challenges. Even a winding road going up a mountain follows the same principle.

The angle of the slope is a critical factor. A (39) __________ slope makes it easier to push an object, but it also means the ramp has to be much longer to reach the same height. To move (40) __________ heavy object, engineers must find the right balance. They must (41) __________ enough force to overcome gravity and friction, but the ramp helps to minimize how much is needed.

The inclined plane is an elegant demonstration of a key physics concept. It allows us to accomplish difficult tasks by spreading the work out over a greater distance. The fundamental (42) __________ is that while the total amount of work done remains the same, the force required is reduced. This simple idea has had a massive impact on construction and engineering throughout history.

Dengue fever is a viral infection that has become a significant public health concern in tropical and subtropical regions, including Vietnam. Transmitted by the bite of an infected Aedes mosquito, the disease can affect anyone, but its prevention is something in which everyone, including teenagers, can play a crucial role. While there is no specific medicine to cure dengue, understanding how it spreads and taking proactive steps are the best defenses to protect ourselves and our families.

The symptoms of dengue typically begin four to ten days after being bitten by an infected mosquito. A person with dengue often experiences a high fever, severe headache, pain behind the eyes, muscle and joint pains, and a skin rash. While most people recover within a week or so, some cases can develop into a more severe form known as Dengue Hemorrhagic Fever. This condition can be life-threatening and requires immediate medical attention, which is why recognizing the initial symptoms is so important.

The primary carrier of dengue, the Aedes mosquito, is easily identifiable by the white markings on its legs. Unlike other mosquitoes that are most active at night, the Aedes mosquito typically bites during the daytime. It breeds in small pools of clean, standing water often found around homes. Flower pots, old tires, discarded containers, and even blocked roof gutters can become potential breeding grounds. These locations are often overlooked. They can be found both inside and outside the home, making constant vigilance a necessity.

The most effective way to prevent dengue is to eliminate mosquito breeding sites. This is a simple but powerful action that everyone can participate in. Regularly, you should empty water from flower pot saucers and other containers. Large water storage tanks should be tightly covered to prevent mosquitoes from laying eggs in them. It is also important to dispose of any rubbish, such as old bottles, cans, and tires, that can collect rainwater. By keeping our living environment clean and free of standing water, we disrupt the mosquito's life cycle.

In addition to controlling mosquito populations, personal protection is also vital. When outdoors, especially during peak biting hours in the early morning and late afternoon, using an effective mosquito repellent is highly recommended. Wearing light-colored, long-sleeved shirts and long pants can also provide a physical barrier against bites. At home, installing screens on windows and doors can prevent mosquitoes from entering. These simple habits significantly reduce the risk of being bitten.

In conclusion, fighting dengue fever is a shared responsibility. It does not require complex technology or expensive resources. Instead, it relies on community awareness and consistent, simple actions taken by individuals and families. By eliminating breeding grounds and protecting ourselves from bites, we can create a safer community for everyone.