Đề ôn thi Đề thi vào lớp 10 Trường Phổ thông Năng khiếu môn Tiếng Anh - Mã đề PTNK-87

Have you ever wondered how your smartphone screen knows exactly where you touch it? Most modern mobile devices use what is called a capacitive touchscreen. The screen is not just one piece of glass; it is made of multiple layers. The top layer is often made of a special, durable glass, and beneath it are layers that conduct electricity.

These conductive layers have a constant, invisible electrical field across them. When your finger, which is also conductive, touches the screen's surface, it (21) __________ this electrical field at the precise point of contact. This change in electrical charge is tiny, but it's enough for the device to detect. The screen does not feel pressure; it only senses this electrical change.

The device's controller, a component which is part of the processor, then immediately (22) __________ where the disruption occurred. A user manual might state that a user should touch the screen with a bare finger for the technology to work correctly. This location data is then sent to the phone's operating system, which carries out the command you intended, like opening an app.

This entire process works (23) __________ the human body can conduct electricity. The natural moisture and salts on your skin make your finger a perfect tool for this interaction. This unique property allows the device (24) __________ your gestures and taps with incredible accuracy. You can see why using a regular plastic pen does not work on your phone screen!

So, the next time you use your phone, remember the simple but brilliant science at play. It is a great example of clever engineering that we use every day. Understanding it is not too difficult once you get the hang of it. If human skin were not conductive, this amazing technology would not exist today.

Dengue fever, often called "breakbone fever," is a serious mosquito-borne illness affecting millions globally each year. Predominantly found in tropical and subtropical regions, this viral infection poses a significant public health challenge, causing severe illness and potentially death. [I] Its global spread remains a concern, impacting daily life in affected communities. Understanding this invisible threat is the first step towards effective protection.

In Vietnam, dengue fever is a familiar and recurring challenge, especially during annual rainy seasons. Frequent outbreaks make it a critical public health priority. Recognizing this persistent threat, the Ministry of Health (Bộ Y tế) consistently launches widespread public awareness campaigns. These initiatives often highlight community involvement, urging families to prevent the disease's spread. The message is clear: collective action is essential to combat this tiny, yet dangerous, adversary affecting countless Vietnamese households annually.

Dengue is transmitted when an infected Aedes mosquito bites a person. These daytime-biting mosquitoes lay eggs in stagnant water around homes. Common breeding grounds include flowerpots, old tires, water containers, and clogged gutters. [II] Once infected, symptoms can range from mild to severe. Typical signs include high fever, severe headache, pain behind the eyes, joint and muscle pain, and skin rash. In its more severe form, dengue hemorrhagic fever, it can lead to bleeding, shock, and be life-threatening without treatment.

As a young person, you may wonder how this affects you. [III] Dengue is a very real risk in your community, and you have a vital role in protecting yourself and loved ones. Practical actions start at home. Regularly check your surroundings for standing water and eliminate it. Emptying flowerpot saucers, clearing clogged drains, and properly covering water tanks are key steps. For personal protection, use mosquito repellents, wear long sleeves and pants, especially during peak biting hours, and consider mosquito nets for sleeping.

These small actions collectively make a huge difference in reducing mosquito populations and dengue transmission. By taking initiative, you not only safeguard your own health but also contribute to the well-being of your family and neighborhood. Remember, protecting your family from dengue isn't just the job of health authorities; it's a shared responsibility beginning with household awareness and active participation. Your efforts are crucial in creating a healthier, dengue-free community for everyone. [IV]