Why do women in some countries wear veils?

A veil is a piece of cloth that is usually worn to hide a person’s hair or face. Women have worn veils since ancient times—mostly in Middle Eastern countries— primarily to keep men from looking at them. Many women of the Muslim faith still wear veils of some type when they are out in public. In some Muslim countries, only a woman’s eyes are allowed to show.

Although Westerners (people from North America and Western Europe) may find these veils symbolic of women’s restricted freedoms in many Muslim societies, Muslim women wear them to honor long-held traditions of modesty and to show respect for their religion and the men in their lives.

Why do insects have eyes with thousands of lenses?

Most adult insects, including bees and dragonflies, have two large compound eyes, made up of separate, sometimes thousands, of lenses. They all point in different directions to give the insect a very wide field of vision.

The lenses also help the insect see movement, enabling it to react quickly to seize its prey or escape danger. You can witness this yourself as you try to swat a fly in your home it’s almost impossible to catch a flying insect!

How do police officers help the community?

There are about 800,000 police officers in the United States. Police officers protect the lives and property of citizens. They maintain order, catch lawbreakers, and work to prevent crimes. Also called “peace offers,” police officers have different responsibilities depending upon the size and structure of the communities in which they serve.

Police officers may patrol the streets on foot or in squad cars, control traffic, or work as detectives investigating crimes. At the police station, officers may be assigned to work in the crime laboratory or the records department. All officers file reports of incidents, and many testify at trials and hearings.

Are there plants that do not grow from seeds?

Yes. Not all plants are seed plants. Some plants, such as ferns and mosses, reproduce with spores instead of seeds. Spores, like seeds, can survive harsh conditions and develop into new plants. However, unlike seeds, spores are produced without fertilization and contain neither a plant embryo nor endosperm. Some plants can reproduce without spores or seeds through vegetative reproduction, in which a part of the stem or root gives rise to a new plant.

Why are rain clouds gray?

Rain clouds are generally dark gray because light cannot penetrate them due to the deep and densely packed water droplets and ice inside the cloud. Generally, the color of a cloud depends on the cloud’s relationship to the sunlight: Clouds appear gray when they block sunlight.

The thicker the cloud, the more light it blocks. When a cloud is about 3,000 feet (914 meters) thick, hardly any sunlight will make its way through the cloud.

What is a “kissing bridge”?

Kissing bridges are covered bridges with roofs and wooden sides. They are called kissing bridges because people inside the bridge cannot be seen from the outside, making them good places to kiss discreetly. They were first built in the nineteenth century by engineers who designed coverings to protect the structures from the effects of the weather.

More than 10,000 covered bridges were built across the United States between 1805 and the early twentieth century. As of January 1980, only 893 of these covered bridges remained—231 in Pennsylvania alone, where the first one was erected.

Can my cat or dog benefit my health?

As a matter of fact, yes! Researchers believe that regular contact with pets can reduce levels of stress and reduce blood pressure (the force of blood pushing against the walls of the arteries as the heart pumps out blood).

Pets offer stability, comfort, security, affection, and intimacy. Owning a dog also provides a great opportunity to get exercise and fresh air, since it will need to go for a walk every day.

Which was the biggest dinosaur?

Information about dinosaurs changes all the time as new bones are found and new evidence about their surroundings becomes available. The largest complete dinosaur fossil found by paleontologists (scientists that study dinosaurs) was Brachiosaurus (meaning “arm lizard”), a huge dinosaur that lived during the Jurassic Period. It weighed about 80 tons (72,640 kilograms) and reached 75.5 feet (23 meters) in length and 39 feet (12 meters) in height—about the length of two large school buses and the height of a four-story building. Parts of leg bones and vertebrae of even larger dinosaur species have been discovered, and scientists have studied these parts to try and determine their exact size.

Several of these—such as Argentinosaurus and Amphicoelias—might have been one and a half to two times larger than Brachiosaurus. The Argentinosaurus, thought to weigh as much as 100 tons (90,800 kilograms), was uncovered in the late 1990s in Argentina, which was home to many of the world’s largest dinosaurs. These gentle giants were once thought to live in watery, swampy regions, but recent evidence suggests that most of them were forest dwellers that ate leaves from the tops of trees. They had enormous bodies, very long necks, relatively small heads, and thick, tree-trunk-like legs, much like an elephant’s legs. They moved very slowly and did not have many ways to defend themselves, but their tremendous size kept most predators away.

How hot is the Sun?

The Sun is extremely hot. The surface of the Sun (or its outer visible layer, called the photosphere) is about 10,000 degrees Fahrenheit (5,537 degrees Celsius)— about 50 times the temperature required to boil water.

The core of the Sun, where solar energy is created, reaches 27 million degrees Fahrenheit (15 million degrees Celsius). It is so intense that nuclear reactions take place there.

How does the metal switch in a toaster bend?

It bends because it is made of two metals that are joined together, something called a bimetal switch. One metal (usually brass) expands quickly when heated, while the other expands much more slowly. This difference causes the switch to bend toward the low-expansion metal.

Bimetal switches are used in other appliances that switch electricity on and off to keep their temperatures even, like irons and refrigerators. The thermostat that regulates the temperature of your home by turning your furnace and air conditioner on and off also uses a bimetal switch.