第 7 单元 - 第 1 课

A tooth is a hard, calcified structure found in the human mouth that plays a crucial role in biting, chewing, and speaking. It is composed of different layers, including enamel, dentin, and pulp. The enamel forms the outermost protective layer, while the dentin provides support and structure. Within the tooth's core lies the pulp, which contains nerves, blood vessels, and connective tissue. Teeth come in various types, including incisors, canines, premolars, and molars, each serving a specific function in the process of breaking down food. Maintaining oral hygiene and regular dental care are essential for preserving the health and integrity of teeth.

A comb is a personal care tool with evenly spaced teeth or bristles that is used to detangle and style the hair. It helps to remove knots, distribute hair products, and create desired hairstyles by smoothly running through the strands. Combs come in various sizes, materials, and designs, offering versatility and convenience for different hair types and styling needs.

Breakfast refers to the first meal of the day, typically consumed in the morning after waking up from sleep. It is often considered the most important meal as it provides the body with essential nutrients and energy to start the day. Traditional breakfast foods vary widely across cultures but commonly include items like cereal, eggs, toast, fruit, and beverages such as coffee or tea.

Dinner typically refers to the main meal of the day, traditionally eaten in the evening or late afternoon. The exact timing of dinner can vary depending on cultural norms and personal schedules. It often consists of a substantial spread of dishes, including a protein source, such as meat, fish, or tofu, starches, like rice, potatoes, or pasta, vegetables, and sometimes soup or salad. Dessert may follow the main course, featuring sweets like cakes, pies, or fruit. Dinner provides an opportunity for individuals and families to come together, share a meal, and unwind after a busy day.

A television (TV) is a device used to receive and display broadcasted or streamed video and audio content. It allows viewers to watch shows, movies, news, and other programming on a screen. Televisions come in various sizes and types, including traditional cathode ray tube (CRT) models, flat-panel LCD and LED screens, and advanced 4K and OLED displays. Modern televisions often include features such as internet connectivity for streaming services, smart TV capabilities for accessing apps, and high-definition resolution for clearer, more detailed images.