English Grammar, Science, and Speech: A Comprehensive Guide

English Grammar

Past Perfect

The past perfect tense describes actions that happened before another action in the past. It is formed using "had" + past participle.

Examples:

• I had worked for my uncle.
• I had met him before you introduced us.
• We had gotten married before 1985.

Third Conditional

The third conditional describes a hypothetical situation in the past that did not happen. It is formed using "if" + past perfect + "would have" + past participle.

Example:

If I had had enough money, I would have bought you a house. (Si hubiera tenido suficiente dinero, te hubiera comprado una casa)

Science

Celestial Bodies

Celestial bodies are objects in the universe that interact with each other through gravity. They can be classified into two types:

• Those that emit light (e.g., stars)
• Those that reflect light (e.g., planets)

Human Body Systems

The human body is composed of several interconnected systems, including:

• Nervous system: A network of nerves and cells that transmit messages between the brain and the body.
• Muscular system: Enables movement and vital functions through muscle contractions.
• Circulatory system: Transports blood, oxygen, and nutrients throughout the body.
• Digestive system: Breaks down food and absorbs nutrients.

Vital Functions

Vital functions are essential for life and include processes like breathing, circulation, and digestion. Without these functions, we would not survive.

Periodic Table

The periodic table organizes chemical elements according to their atomic number and properties.

Electron

An electron is a negatively charged particle that orbits the nucleus of an atom.

Speech

A speech is a formal expression of thoughts, reasoning, feelings, or desires, delivered orally or in writing. Its primary function is to communicate and persuade.

Parts of a Speech

• Exordium: Captures the audience's attention and goodwill.
• Exposition/Narration: Presents the main points and facts supporting the speaker's argument.
• Argumentation: Provides evidence to support the speaker's claims.
• Peroration: Summarizes the key points and leaves a lasting impression on the audience.

Artificial Intelligence

Artificial intelligence (AI) refers to the ability of machines to learn, understand, reason, make decisions, and perceive reality. The first AI was created in 1997.

Environmental Pollution

Environmental pollution is a global issue with severe consequences for human health and the planet. It contributes to various diseases and disrupts our daily lives. We must raise awareness and take immediate action to address this problem.