第七单元 - 词汇

Biology is the study of living organisms, including their structure, function, growth, and interactions with their environment. It covers a wide range of topics, from the molecular mechanisms within cells to the behavior of entire ecosystems. Biology helps us understand the diversity of life on Earth, how organisms adapt to their surroundings, and the processes that sustain life, such as metabolism, reproduction, and evolution.

The idiom "teacher's pet" originated in the late 19th or early 20th century and is used to describe a student who is particularly favored by a teacher or seen as the teacher's favorite. The phrase suggests that the student receives special attention, privileges, or preferential treatment from the teacher, potentially due to their exceptional academic performance or exemplary behavior. However, the term is often used in a slightly derogatory manner to imply that the student may be excessively eager to please the teacher and gain advantages, which can lead to resentment from other students.

The origin of the idiomatic expression "lend a hand" can be traced back to the literal act of physically assisting someone by extending a hand to offer support. It has likely emerged from the universal understanding of reaching out and offering help to those in need. Over time, this idiom have become deeply ingrained in language and culture, emphasizing the importance of being helpful, supportive, and compassionate towards others.

The idiom "with flying colors" is believed to have originated in the 16th century. At the time, flags were used to signal victory in battle. A flag that was flying high and undamaged was seen as a sign of victory, while a flag that was damaged or lowered was seen as a sign of defeat. The phrase "with flying colors" came to be used to describe a person or group who had achieved success or victory. It suggests that the person or group has performed exceptionally well and has surpassed expectations.

The idiom "piece of cake" is used to describe something as very easy or simple to accomplish. It likely originated from the idea that eating a piece of cake is enjoyable and requires little effort. The phrase has been in use in English since the early 20th century and has become a popular way to express how easy a task is.

Mathematics is the study of numbers, quantities, shapes, and patterns. It includes various fields like arithmetic, algebra, geometry, and calculus, all of which are used to solve problems and explain relationships between different elements. Mathematics is essential in everyday life and is widely applied in areas such as science, engineering, economics, and technology.