However, it's essential to note that the Great Wall is not a single entity but a complex network of walls, fortifications, and defensive systems built across different dynasties and periods. The oldest sections of the wall date back to the 7th century BC, while the most recent sections were built in the 20th century AD. Consequently, the Great Wall is a testament to the enduring legacy of China's rich history and archaeological heritage.”

“嗯，很不错，你先坐下。”英语老师让他坐了下来。

“旁边的女生，请你来介绍一道你喜欢的菜。”又开始点其他的人。

“是，老师。”李佳站了起来，思索着自己该介绍哪一道喜欢的菜。

“ Spicy Chicken Cubes is a delicious Sichuanese household dish that combines the perfect balance of spice and flavor. Made with chicken, green and red bell peppers, garlic, ginger, scallions, and dried chili peppers, this dish is a culinary masterpiece.

Here's a step-by-step guide on how to make Spicy Chicken Cubes:

1. Wash the chicken and remove the bones. Cut the chicken into small cubes.

2. Marinate the chicken cubes with 生抽、料酒、黑胡椒粉、盐和淀粉，搅拌均匀，腌制 30 分钟。

3. Cut the green and red bell peppers into small cubes.

4. Heat oil in a wok or large skillet over medium-high heat. Fry the chicken cubes until golden brown, and then remove them from the oil.

5. In another pan, heat a little oil and stir-fry the garlic, ginger, scallions, and dried chili peppers until fragrant.

6. Add the fried chicken cubes back to the pan, along with the bell peppers.

7. Mix well and cook for another minute.

8. Finally, sprinkle with sesame seeds and serve hot.

As for the taste, Spicy Chicken Cubes is characterized by a delightful combination of spicy, numbing, and savory flavors. The crispy chicken cubes are tender and well-seasoned, complemented by the crisp bell peppers and aromatic spices

第86章 要遵守校规哦！13

the direction perpendicular to the beam. This effect was initially discovered by British physicist John Tyndall in 1869, hence its name.

The formation principle of the Tyndall effect is related to light scattering. When light passes through a colloid, it interacts with the particles suspended within the colloid. If the diameter of the particles is smaller than the wavelength of the light, the particles will scatter the light in all directions. This results in a diffuse glow around the light beam, which is the Tyndall effect.

The Tyndall effect is observed in both natural and artificial colloids. Some examples of colloids include milk, fog, and certain types of paint. In these materials, the scattering of light by the particles suspended in the solvent creates a characteristic blue haze or glow when viewed under a light source.

The Tyndall effect has several practical applications:

1. suspensions: In the field of chemistry and materials science, the Tyndall effect is used to study the properties of suspensions, which are materials composed of small particles dispersed in a liquid or gas. By analyzing the degree of scattering of light in different directions, researchers can determine the size, shape, and concentration of the particles.

2. aerosols: In environmental science, the Tyndall effect is used to study aerosols, which are small particles suspended in the atmosphere. By measuring the amount of light scattered by aerosols, scientists can estimate their concentration and size, which is important for understanding their impact on climate and health.

3. lithography: In the semiconductor industry, the Tyndall effect is used in lithography to pattern and etch microchips. By controlling the size and distribution of particles in a colloidal solution, researchers can create intricate patterns on the surface of a substrate.

4. cosmetics: In the cosmetic industry, the Tyndall effect is used to create pearlescent effects in products such as nail polish, hairspray, and eyeshadow. The Tyndall effect gives these products a unique appearance and texture.

5. art: Artists have also utilized the Tyndall effect to create visually striking effects in their paintings and sculptures. By suspending particles in a transparent medium, they can create a sense of depth and luminosity in their works.

In summary, the Tyndall effect is a fascinating optical phenomenon that occurs when light passes through colloids.

第87章 要遵守校规哦！14

the direction perpendicular to the beam. This effect was initially discovered by British physicist John Tyndall in 1869, hence its name.

The formation principle of the Tyndall effect is related to light scattering. When light passes through a colloid, it interacts with the particles suspended within the colloid. If the diameter of the particles is smaller than the wavelength of the light, the particles will scatter the light in all directions. This results in a diffuse glow around the light beam, which is the Tyndall effect.