What is a computer virus?

A virus is a malicious software program that infects computer files or hard disk drives and then makes copies of itself. Many activities that kids do online can leave computers vulnerable to viruses. E-mail attachments are a common means of distributing viruses, but viruses can also be downloaded when you share files and open instant message attachments. In order to keep your computer safe, never open an e-mail attachment you haven’t requested.

Send an e-mail to friends to confirm that they meant to send you an attachment. Also, you can configure your instant messaging program so you can’t receive files from other users. Never download any program without checking with a parent first. You can protect your computer by always running up-to-date firewall software, by running antivirus software regularly, and by periodically scanning your computer for spyware or other unwanted software and immediately removing it.

When were the hottest and coldest days of the year?

In the United States, the hottest day that we know of was July 10, 1913. On that day, Death Valley, California, reached 134 degrees Fahrenheit (56 degrees Celsius). The highest temperature in the world was recorded on September 13, 1922 in Al Aziziyah, Libya, where it reached 136.4 degrees Fahrenheit (58 degrees Celsius).

The coldest temperature ever measured was –129 Fahrenheit (–89 Celsius) at Vostok, Antarctica, on July 21, 1983. The world’s most extreme temperatures take place in Verhoyansk, northeast Siberia, where temperatures fall as low as –90 degrees Fahrenheit (–68 degrees Celsius) in winter and rise as high as 98 degrees Fahrenheit (37 degrees Celsius) in summer.

Why should I drink lots of water?

All living things need water to survive. Without water, the human body stops working properly. Water makes up more than 50 percent of your body weight and a person cannot survive for more than a few days without it. Water flushes toxins out of your organs, carries nutrients to your cells, and provides a moist environment for ear, nose, and throat tissues.

Water is also in lymph, a fluid that is part of your immune system, which helps you fight off illness. You need water to digest your food, to get rid of waste, and to sweat. Too little water in your body leads to dehydration, and it can make you tired and unable to function. Your body gets water from drinking it, but lots of foods, such as fruits and vegetables, contain water too.

Why is a concise promotion called a “blurb”?

The word blurb, meaning an inspired recommendation, comes from an evening in 1907 during an annual trade dinner of New York publishers Where it was customary to distribute copies of new books with special promotional jackets. For his book, humorist Gelett Burgess caused a sensation with a cover drawing of a very attractive and buxom young woman whom he named “Miss Belinda Blurb.” From then on, any flamboyant endorsement would be known as a blurb.

Why do we call a quarter “two bits”?

European settlers brought their money with them to America, and coins made of precious metal were accepted everywhere at face value. The Spanish peso was divided into eight silver coins, which the English called bits, or pieces of eight.

Two bits was one-quarter of a Spanish dollar. When money was printed and minted in the new world, although a dollar’s coinage was divided by ten, the expression “two bits” continued to mean one-quarter of a dollar.

What are coral reefs?

Tropical coral reefs are ridgelike or moundlike structures composed of corals and other aquatic organisms. They border the shorelines of more than 100 countries. Although coral reefs comprise less than 0.5 percent of the ocean floor, it is estimated that more than 90 percent of marine species are directly or indirectly dependent on them—they are home to approximately 4,000 species of fish alone.

Reefs protect human populations along coastlines from wave and storm damage by serving as buffers between oceans and near-shore communities. The Great Barrier Reef, located in northeast Australia’s Coral Sea, measures 1,616 miles (2,000 kilometers) in length. It the largest living structure on Earth, and can be seen from the Moon.

How long is the giant anteater’s tongue?

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.

Why is someone lost if he “doesn’t have a clue”?

The original spelling of clue was C-L-E-W, and its forgotten meaning is a “ball of yarn or string.” A clew of string was unravelled as a guide out after entering an unfamiliar maze or a cave. If you became lost, all you had to do was follow the string back to the point of origin. In the modern cliché, if someone “doesn’t have a clue,” he is in the dark with no idea how to get out of his dilemma.

Why is going to bed called “hitting the hay”?

When going to sea, early sailors had to provide for their own bedding. This need was catered to by merchants on the docks who, for a shilling, sold the seamen crude canvas sacks stuffed with hay. When heading off to sleep, a sailor would announce that he was going to “hit the hay.” Although less crude than those coarse canvases, early North American settlers also used hay to stuff mattresses and pillows, so when going to bed, they too would “hit the hay.”

Why do people have to grow old?

Growing old is part of being a living thing. Every plant and animal must go through a cycle of life that involves a beginning, a middle, and an end. Actually, as soon as we are born we begin aging or growing older. But when we talk of growing old we think of the physical changes that occur when bodies cannot grow and repair themselves as they once did.

At about age 30 the signs of aging start to appear, though for most people the physical changes are not really obvious until many years later.