2 . Walled Cities Of The World

There are numerous historical walled cities across the world, whose walls date back several centuries. These walls were fortification (碉堡), a necessity throughout medieval eras for defense. They have been preserved as historical monuments and popular tourist attractions in the modern time.

York, England

The city of York is a medieval city situated in the north of England. Historically, the city was ruled by the Romans, Angles, and the Vikings before being incorporated as part of the Kingdom of England in 954. Located in the city are walls built in 71 AD which have been restored and extended with time.

Xi’an, China

The city of Xian is one of the oldest cities in China. It prospered economically as the eastern last station of the Silk Road. The existing walls were originally built in 770 BC and reconstructed in the 14th century under the Ming Dynasty. The walls are well preserved and are a major tourist attraction in the city.

Quebec City, Canada

Quebec City was a colonial (殖民地的) town which was fortified by the settling Europeans. The walls began to be built in 1608 under both British and French regimes (政权). A fort was constructed by the British as an additional defensive measure and remains undamaged to date. The city’s fortifications were listed as a UNESCO World Heritage Site in 1985.

Mexico City, Mexico

Historically, the City of Mexico gained importance as the Aztec Capital. The Spanish then drove out the Aztecs and rebuilt it as the Spanish Capital. The walls protecting the city were built in 1521. Mexico City is also home to numerous colonial-era buildings which together with the walls are major tourist attractions in the city.

5 . Many popular modern board games were invented in the United States. But some of our favorite games came from other countries and have deep historic roots.

Parcheesi came from India, where it is known as pachisi. The Mogul King Akbar, who ruled India in the 1500s, actually had a life-sized version of pachisi in his garden. Parcheesi came to America around 1870, and now has many variations of it — where each player has four pawns (兵) and races to be the first one to get them all safely to a home base.

Though simpler than Chess, Checkers offers plenty of strategic considerations for its players. Developing from a Middle Eastern game called alquerque, Checkers was introduced to America in the 1930s and has a number of variations that have been played since at least 3000 B.C.

Backgammon originated in Mesopotamia around 3000 B.C. In the game, two players took turns rolling dice in a race to be the first one to get their 15 pieces off the board. Introduced to America in 1920, Backgammon became wildly popular then and remains so today, especially in its electronic version.

Mancala means “to move” in Arabic. Players take turns to move pieces on its special board until all the pieces have been captured. Ancient game boards dating from the 6^th and 7^th centuries have been found carved in stone in Ethiopia. Mancala was brought into America in 1940 by immigrants from Cape Verde in Africa. And yes — it is played online!

7 . Imagine a world without money. With no way to buy stuff, you might need to produce everything you need unless you could figure out how to exchange some of the things you made for other items.

Economists like me believe that using money makes it much easier for everyone to specialize, focusing their work on a specific activity. As economists have known since David Ricardo’s work in the 19th century, there are gains for everyone from exchanging goods and services-even when you end up paying someone who is less skilled than you.

People have traded goods and services with one kind of money or another, whether it was trinkets, shells, seeds or cash for tens of thousands of years. People have always obtained things without money too, usually through barter. It involves exchanging something, such as a cookie, for something else-like a pencil.

Bartering sounds convenient, but it’s hard to pull off. Let’s say you’re a carpenter who makes chairs and you want an apple. You would probably find it impossible to buy one. Just imagine what a trouble it would be to drag the chairs you’ve made to the shopping mall in the hopes of cutting great deals through barter with the sellers.

Paper money is far easier to carry. You might be able to sell a chair for $50. You could take that $50 bill to a supermarket, buy two pounds of apples for $5 and keep the $45 in change.

Nowadays, of course, many people pay for things without cash or coins. Instead, they use credit cards or make online purchases. Others simply wave a smartwatch at a designated device. Others use bitcoins and other cryptocurrencies. But all of these are just different forms of money that don’t require paper.

No matter what form it takes, money ultimately helps make the trading of goods and services go more smoothly for everyone involved.

8 . You may have seen them standing alone in a farmer’s field. With thin arms and a strange smile, they stand guard over the crops day and night.     1    

Scarecrows have been around since at least the time of the ancient Egyptians. Back then, farmers covered wooden frames with nets to protect wheat fields.     2     Around 2500 BCE, the Greeks made the first human-like scarecrows. They added a face which was similar to that of the Greek god Priapus.     3     The Romans later copied this design and brought it to Europe.

Centuries after the Romans marched through Europe, people around the world were creating their own scarecrows. In Japan, scarecrows were shaped like people in raincoats and straw hats. In Germany, scarecrows were made to look like witches.

    4     In the oldest book of Japanese literature, The Kojiki, a scarecrow named Kuebiko appears. Though he can’t walk, Kuebiko is a kind of all-knowing god. In the mid-19th century, writer Nathaniel Hawthorne brought scarecrows into literature with the short story “Feathertop.” In this tale, a witch who prays to the Devil brings a scarecrow to life.

Then there is the most famous scarecrow. His name is simply “Scarecrow,” and he appears in The Wonderful Wizard of Oz. In the children’s novel, Scarecrow joins Dorothy, Tin Man and the Cowardly Lion on an adventure to meet the wizard of the magical land of Oz.     5    

Aside from these examples, scarecrows have featured in rock songs and as characters in comic books. On Halloween, they are brought out as scary decorations. Both practical and creepy, scarecrows continue to capture our imagination.

9 . In 1810, during his first Grand Tour of Europe, Byron carved his name into a column base of the Temple of Poseidon on the Aegean coast. Although Byron himself might not have actually written the name that is left there, the story has become part of the history of the monument, searched for by his admirers among the hundreds of other names carved all over the temple.

Modern graffiti, however, is met with a very different reaction. In 2014 a Russian tourist was fined €20,000 for carving a large “K” on a wall of the Colosseum in Rome, the fifth such incident that year.

What is the thinking behind such acts? Are tourists aiming for ill fame to become part of the monument’s history? Or is it simply part of the experience of visiting the site? And, further, why is historical graffiti, which was equally destructive, considered historic heritages? The motives behind them are, after all, probably the same, however, graffiti comes to tell us about lives and moments that might otherwise have been lost.

The earliest graffiti of a person’s name on a monument has been identified by the historian Lionel Casson in a cave at Wadi Hammamat in Egypt in 2000 BC. The name of Hena is cut into the sandstone alongside a list of his achievements. In ancient Greece, too, stoas (柱廊) were the meeting places of philosophers and the places for school boys’ lessons. We therefore often see alphabets and Homeric poems written on their walls.

And it is not just monuments and buildings: Miltiades, a general from the Battle of Marathon in 490 BC, carved his name into the helmet he wore. In the Athens, too, a Spartan shield (盾) was found with words noting that the Athenians captured it during the Battle in 425 BC. Without such graffiti, the objects would still be impressive, but far less useful for historians, as their writing provides an exact original place.

In the 21^st century, however, with the rapid increase in tourism, if everyone decided to leave their mark, these sites would be irretrievable (不可挽回地) destroyed. Perhaps Beijing’s controversial new free graffiti zones on certain sections of the Great Wall of China will satisfy the desire to carve our own piece of history into the limited resource of the monument, though it seems unlikely that it will easily be contained to one area. Regardless, it is important that we protect these monuments — and the graffiti that some of them already contain.

10 . How far back does your family tree go? A hundred years? A thousand years? What about 6 to 7 million years? An ancient skull (颅骨) found in Africa suggests that the human family might be that old.

Discovered in 2001 in the desert of Chad, the skull was nicknamed Toumai by scientists, Toumai is a rare find. The skull is nearly complete; it even includes a few teeth. The Tournai skull is estimated to be between 6 and 7 million years old. Scientists are debating whether the skull is linked to humans.

The finding is not without controversy. Some scientists think that Toumai is the oldest known hominid (人种)，or primitive human ancestor, ever found. Others say Toumai is an ape.

Most hominids that scientists are aware of lived millions of years after Toumai. The most famous one is called Lucy. She lived in Ethiopia about 3.5 million years ago. While Lucy's face looked like the face of a chimpanzee, Toumai's skull has both human and apelike features.

Because Toumai’s skull looks different from other hominid skulls, some scientists think Toumai represents a whole new species. Toumai’s official name is Sahelanthropus tchadensis .

Scientists were surprised to find a human-like face on a skull as old as Tournai’s. They thought hominids turned into humans step by step over time. Scientists mark those changes on a timeline, starting with a chimpanzeelike ancestor and ending with modern humans. Toumai’s human-like face and chimp-sized brain suggest that the development of hominids was not so simple. There may not be a direct line leading from Tournai to Lucy to us. Instead, the timeline might resemble a tree with lots of branches. Different species in different places could have evolved human-like features at different times.

Scientists aren’t sure where exactly Toumai belongs on our family tree. Toumai could be like a great- greatgrandfather —or just a distant cousin. Toumai could also be one of many types of hominids who wandered Earth millions of years ago.