Đề ôn thi Đề thi vào lớp 10 Trường THPT Chuyên KHXH môn Tiếng Anh - Mã đề KHXH-04

A (35) __________ misconception about the seasons is that they are caused by Earth's changing distance from the Sun. Many people believe that Earth is closer to the Sun in summer and farther away in winter. While our planet's orbit is slightly elliptical, this distance variation is not the primary reason for the change in seasons. The real cause is something far more interesting and fundamental to our planet's position in space.

The actual reason for the seasons is the tilt of Earth’s axis. Imagine an imaginary line running from the North Pole to the South Pole; this is Earth's axis of rotation. However, this axis is not straight up and down. Instead, it is tilted at an angle of about 23.5 degrees. (36) __________ means that as the Earth travels around the Sun, different parts of the planet receive the Sun's rays more directly at different times of the year.

As the Earth (37) __________ its year-long orbit around the Sun, this axial tilt remains pointed in the same direction in space. This causes one hemisphere to be tilted towards the Sun while the other is tilted away. The hemisphere tilted towards the Sun experiences summer because the sunlight hitting it is (38) __________ and concentrated. This leads to longer days and warmer temperatures.

(39) __________, the hemisphere tilted away from the Sun receives less direct, more spread-out sunlight. The sun's rays arrive at a lower angle, which means the energy is less intense. This results in shorter days and colder temperatures, which is why this hemisphere (40) __________ experience winter. The spring and autumn seasons are transitional periods when neither hemisphere is tilted significantly toward or away from the Sun.

(41) __________ that this constant tilt, rather than a variable distance, is the key factor. The effect is entirely about the angle of sunlight. (42) __________, it is the orientation of Earth’s axis relative to the Sun, not its proximity, that governs the cycle of seasons, giving us the wonderful variety of weather we experience throughout the year.

In the life of a teenager, juggling school, friends, and hobbies can feel like a superpower. But what if the most potent superpower was not about doing more, but about resting effectively? For teenagers, a good night's sleep is not a luxury; it is a biological necessity. While adults need 7-8 hours, scientific evidence shows that adolescents require 9 to 10 hours of sleep per night for optimal brain function, emotional regulation, and physical health. Unfortunately, the pressures of modern life mean most teens get far less.

The science behind this need is clear. During the teenage years, the body's internal clock, or circadian rhythm, naturally shifts, making teens feel tired later at night and want to wake up later in the morning. This is not laziness; it is biology. While sleeping, the brain is hard at work. It consolidates memories from the day, strengthening the neural pathways that are essential for learning and studying for exams. This process is crucial for academic success, allowing a student to recall information more effectively. Without adequate sleep, this vital work is cut short.

In Vietnam, this challenge is particularly intense. The deep-rooted culture of 'học thêm' (extra classes) often means a student's day does not end when school does. Many attend evening classes that run late, leaving them with a difficult choice: sacrifice sleep to finish homework or sacrifice study time for rest. This dilemma creates a vicious cycle of exhaustion. Vietnamese teenagers often find themselves burning the midnight oil, and as a result, they arrive at school the next day too tired to fully absorb the lessons they studied so hard for.

The consequences of chronic sleep deprivation extend beyond poor grades. A tired teenager is often an irritable one, leading to strained relationships with family and friends. It can also weaken the immune system, making them more susceptible to illnesses. Furthermore, a lack of sleep can directly affect physical appearance, often contributing to skin problems like acne. Essentially, skimping on sleep undermines a teenager's ability to be their best self, both academically and socially.

Recognizing sleep as a superpower is the first step. The solution is not to abandon ambitions but to integrate sleep into the strategy for success. Creating a consistent sleep schedule, even on weekends, can help regulate the body's clock. Reducing screen time from phones and computers an hour before bed can also improve sleep quality. By viewing sleep as a critical component of their study routine, not an obstacle to it, teenagers can unlock their full potential and truly thrive.