第 6 单元 - 参考

The brain is the complex and intricate organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It controls and coordinates all bodily functions, including sensory perception, motor activity, thought, and emotion. The brain is made up of billions of interconnected neurons that communicate with each other through electrical and chemical signals, forming neural networks that enable learning, memory, and cognitive processes. It is protected by the skull and nourished by the circulatory system, and its proper functioning is essential for maintaining health and survival.

The idiom "have one's interests at heart" has evolved naturally over time as a way to express the concept of genuine care and concern for someone's well-being or desires. The phrase reflects the inherent human tendency to prioritize the interests and happiness of those we value or have a close relationship with. Its origin lies in the intrinsic qualities of empathy, compassion, and trust that have been integral to human interactions throughout history. Over time, the idiom has become ingrained in everyday language, representing the idea of selflessness and genuine intentions towards another person's best interests.

The phrase "one's heart sink" has been in use since at least the 17th century, and its origin lies in the metaphorical connection between emotions and physical sensations. It is often employed when expectations are shattered, unfavorable news is received, or a realization of an undesirable outcome occurs. This expression can be used in personal narratives, literature, conversations, or everyday language to depict the emotional response to events such as failed plans, unexpected setbacks, or disappointing revelations.

The idiom "face the music" originated from the world of theater, where actors were required to face the orchestra pit (known as the "music") when receiving either applause or booing from the audience. It is commonly employed when someone is responsible for their behavior, whether it's in personal relationships, professional settings, or legal matters.

The phrase "save face" originated in East Asia, particularly in China and Japan, where the concept of "face" refers to one's social standing, reputation, and dignity. In these cultures, losing face is seen as a serious matter, and people will often try hard to avoid it. The phrase was later adopted into English through diplomatic and trade relations with East Asia. The idiom is used to describe the act of avoiding public embarrassment or humiliation by taking actions that preserve one's dignity, reputation, or honor. It implies that someone has made a mistake or is in an awkward or difficult situation, and they are attempting to minimize the damage to their reputation or social standing.

The idiom "down to earth" originated in the late 19th century and is used in various contexts, such as when discussing someone's personality, character traits, or demeanor. It is particularly used to praise individuals who maintain a realistic perspective, exhibit humility, and are relatable to others.

The phrase "have one's hands full" is believed to have originated in the 16th century, and it is a reference to the idea of being so busy or preoccupied that one has no free hands. The idiom is used to describe a situation where someone is very busy or has a lot of responsibilities to attend to. It can be used in both personal and professional contexts.

The idiom "old hand" has origins that trace back to the 19th century. It is believed to have originated in the context of card games, particularly poker or similar gambling games. In these games, experienced players who were skilled and knowledgeable were referred to as "old hands." These individuals were seen as having a wealth of experience and expertise, making them formidable opponents. This expression is an idiomatic expression used to describe someone who is highly experienced, skilled, or knowledgeable in a particular field, activity, or job. It signifies a person who has been doing something for a long time and has acquired significant expertise and competence.

The origin of the phrase "land on one's feet" is believed to come from the image of a cat falling from a height and always landing on its feet. The phrase suggests that someone is able to recover from a difficult situation and emerge successfully, much like a cat that always lands safely on its feet. It is used to describe a situation where someone is able to recover from a difficult situation and come out of it successfully. It implies that the person is resilient and able to adapt to changing circumstances in order to achieve success.

The phrase "run off one's feet" is believed to have originated in the early 20th century. This idiomatic phrase is used to describe a situation where someone is extremely busy and has a lot of tasks to complete.