Both bravery and courage are acts of valour and imply a certain strength and fearlessness. There is, however, a subtle difference in meaning between the two words. Courage comes from the French word coeur, meaning heart. It is a quality of character that allows someone to carry through with a difficult premeditated plan of action.
Bravery, on the other hand, comes from the Spanish word bravado, meaning a single or spontaneous act of valour. It is not planned, but rather a kneejerk reaction that often occurs within a crisis.
Libraries offer books for people of all ages, and much, much more—they are places of learning and discovery for everyone. Besides books, public libraries offer videos, DVDs, free access to computers and the Internet, and many literacy-related programs.
For elementary school children, there are variations of the read-alouds and storytelling hours that often include discussions and presentations by the children themselves, as well as summer reading programs. For middle-school kids, there may also be book talks, summer reading programs, creative writing seminars, drama groups, and poetry readings. The more you read, the more you learn! In addition, the library is a place to find information and help with schoolwork. Your school library may offer some of these services as well.
Anteaters are slow-moving mammals with long snouts and claws and no teeth. If you can image it, a giant anteater can grow a tongue up to 2 feet (0.60 meters) long! The anteater uses its long tongue to investigate anthills in South America’s tropical dry forests, rain forests, and savannas.
It sticks its long, sticky tongue down the anthill, twirls it around, and scoops up a mouthful of ants. Anteaters can eat mouthful after mouthful of ants—up to 30,000 per day! It also eats termites and other insects.
The inability to hear, or deafness, can occur for many reasons. Some types of hearing loss result from something blocking sound as it travels from the outer ear to the eardrum and the tiny bones in the middle ear. Other types of loss arise from damage to or a defect of the inner ear or the auditory nerve, which is the nerve that carries sound signals from the inner ear to the brain. Deafness can happen as a result of disease, including severe ear infections, or it can be inherited, with the deafness being apparent at birth or sometimes showing up years later. Injuries and accidents also account for many cases of deafness.
Extremely loud noises, like those that come from an explosion, can cause deafness, though that loss of hearing is sometimes temporary. People who work in noisy factories or those who are frequently exposed to very loud music can also develop hearing loss over time. Many people gradually lose some or all of their hearing when they reach old age, but some of those types of hearing loss can be overcome by wearing a hearing aid, which makes noises like speech or music louder.
The greenhouse effect describes a warming phenomenon. (In a greenhouse, closed glass windows cause heat to become trapped inside.) The greenhouse effect occurs when a planet’s atmosphere allows heat from the Sun to enter, but refuses to let it leave. A good example of the greenhouse effect can be found on Venus.
There, solar radiation penetrates the atmosphere, reaches the surface, and is reflected back into the atmosphere. The re-radiated heat is trapped by carbon dioxide, which is abundant in Venus’s atmosphere. The result is that Venus has a scorching surface temperature of 900 degrees Fahrenheit (482 degrees Celsius). The greenhouse effect can also be found on Earth and in the upper atmospheres of the giant planets: Jupiter, Saturn, Uranus, and Neptune.
Most plants have leaves, even if they do not look like leaves. For example, blades of grass are really leaves. Mushrooms and other fungi do not have leaves, and seaweeds and lichens do not have leaves. Seaweed, a type of algae, also does not have flowers or roots. As an underwater plant, it usually clings to stones, shells, and rocks with its holdfast, a part of the plant that looks like roots. Unlike other plants that feed through their roots, seaweed takes its nutrients from the water in which it grows.
Around 2400 BC, the ancient Sumarians, who used six as their mathematical base, divided a circle into 360 degrees, with each degree subdivided into another 60 parts, and so on. The Romans called these units minute prima, or first small part, and secunda minuta, or second small part. This system was perfect for round clock faces, and that’s why we use minutes and seconds as divisions of time.
Because one meaning of the word “bald” that is not commonly used anymore refers to white markings. “Bald” used to refer to people with white hair. Due to excessive hunting, environmental pollution, and loss of habitat, the bald eagle population became dangerously low at one point, prompting the U.S. Congress to pass a law protecting it. Bald eagles were once listed by the U.S. Fish and Wildlife Service as an endangered species, meaning they were close to being extinct. Thanks to the laws protecting it, these birds have rebounded a bit. They are now listed as threatened, which means they are not as close to being extinct as they once were, but their numbers are still few (only about 50,000 in the United States), and it is illegal to hunt them.
Every country has a national flag, including the United States. Flags date back to around 1000 B.C.E., when the Egyptians used primitive versions of flags—some were even made out of wood or metal—to identify themselves and to signal to others. Ships started using flags at sea to signal to each other and to harbors, often to let them know they had a diseased crew aboard. Flags are still used today to let sailors know what weather conditions await at sea. The military also made use of flags to rally its troops. During the ancient wars, capturing an enemy’s flag was considered an honorable seizure.
Today, the most popular use of flags is to identify and symbolize the world’s countries, which became commonplace in the 1700s. When new lands are discovered—and, for example when Mount Everest and the Moon were conquered—explorers raise their country’s flag as a sign of their being the first to set foot on these unchartered lands.
Dogs bark to communicate with other dogs and with humans. Dogs are descendants of wolves, which are social animals that live in packs, and they share many of the behaviors that define the complex relationships that exist within such animal groups. Few domestic dogs live together in packs (though they often consider their human family their group), but they still use complicated behaviors that involve smell, sight, and hearing to communicate. A dog has many scent-producing glands that it uses to communicate. The scent that a dog leaves behind (in its urine, feces, and paw prints) can reveal its sex, age, and even its mood to other dogs that come sniffing by.
A dog uses its posture, facial expression, and ear and tail position to communicate with other dogs, too. And it uses its voice to communicate by whining, growling, howling, or barking. A dog usually whines or whimpers when it is in distress: when it is hungry, cold, or in pain. Growls indicate that a dog is angry and ready to fight. Barks usually show excitement.