Halloween began with the Celts(凯尔特人),     1     lived in Ireland over two thousand years ago. Back then, the holiday was an end—of summer harvest feast     2     (call) Samhain, a time when food     3     (store) for the winter. Samhain also marked the Celts’ New Year.     4     Samhain Eve, the Celts believed that the ghosts of the dead walked the earth as they crossed to the underworld, and that     5     (fairy) and demons came out of hiding.

Fossil by fossil, the story of the birds becomes clearer. It is now well established that modern birds are actually a group of dinosaurs, which survived a crash between the earth and a small planet 66m years ago. This impact wiped out the rest of the dinosaur world, along with a lot of other creatures.

Recently a paper, published in Nature, has released the details of a fossil, which those studying it believe provides our earliest view of what modern birds were like during the initial stages of their evolutional history. The fossil in question is called Asteriornis maastrichtensis. As its name suggests, the rock containing it was dug from deposits(沉积层)found near Maastricht. These deposits are between 66.8m and 66.7m years old.

This particular rock interested palaeontologists(古生物学家)because it included visible leg bones that looked as though they belonged to a bird. Such ancient fossils are rare, so instead of chancing their arms by using physical or chemical methods to explore the rock for more remains,Daniel Field of Cambridge University and his colleagues employed a CT scan, a process more familiar to most people as a medical-scanning technique. The result, an image of the animal’s skull with false colours added to clarify which bits are which, can be seen in the picture.

Asteriornis maastrichtensis does indeed turn out to be a member of the modern birds. Specifically, it is part of the Galloanserae, which includes both land fowl(家禽),such as chickens and its relatives, and modern waterfowl, like ducks and the like. The skull of Asteriornis maastrichtensis exhibits features of both groups, so it most probably predates the division between them. And its discovery in Europe opens up the debate about whether modern birds originated in the southern part of the earth, as has been proposed.

As to what it looked like when alive, the animal’s left upper leg, its best-preserved bone besides those of its skull, suggests Asteriornis maastrichtensis was a long-legged creature that marched around. This, and evidence that the rock it was preserved in was originally part of a fossil shoreline,has led to reconstructions of modern waterfowl.

Asteriornis maastrichtensis shows that a single fossil can help to nail down previously uncertain dates. The age of the fossil, in fact, suggests that those previous estimates, based on so-called molecular clocks(分子钟),might have overestimated how early the modern birds arose.Based on the discovery of Asteriornis maastrichtensis, the smart money is now on the modern birds as a group being only a little older than the dinosaur-killing impact itself.

The Sanxingdui Ruins site in Sichuan province,     1     (consider) as one of the greatest findings of mankind in the 20th century, has continued to amaze the world. Since May, 2001, more than 500 cultural relics     2     (find) at the site, including bronze ware (青铜器), gold and bronze masks and so on. Among them, a gold mask is catching the world’s attention. It’s 37.2 cm wide, 16.5 cm high and     3    (weigh) about 100 grams, which is strong proof of the existence of ancient Shu state.

6 . The history of inventions leading up to the modern computer is a story of people trying hard to create machines that complete many tasks automatically, such as adding up large numbers, controlling airplanes in flight, etc. Many of the earliest methods of recording and counting data still remain mysteries (something that is not understood).

In England you can visit Stonehenge, where a mysterious collection of large stones has stood since 1,500 BC. Scientists have never discovered the stones’ purpose. However, by observing the way the sun shines between the stones, many people believe Stonehenge was used to predict the seasons and eclipses (蚀) of the sun and the moon.

Another early method of computing was a brass calculator, which existed in Spain nearly 1,000 years ago. The machine was shaped like a human head, with numbers instead of teeth. The shape became its undoing; some people were afraid the machine was supernatural, and destroyed it. In early recorded history, calculators that used the sun, or objects in the night sky, were developed to be used on ships to explore the world beyond the Tigris-Euphrates Valley of southwestern Asia. One such device, dating from the first century, worked with a system of gears designed to track the orbits of stars and planets. These orbits became the marked routes for ships.

In ancient Rome and Greece, one of the earliest machines ever used for processing numbers was the abacus. This simple collection of beads has been used for centuries in China and other Asian countries. The abacus is built with columns of beads attached to a rectangular wooden frame. Inside the wooden frame is a crossbar that separates each column of beads into two sections. In the Chinese version there are two beads above the bar and five below. Each column of beads means a different range of numbers. The first column from the right represents ones, the second tens, the third hundreds, etc. By moving beads, calculations are quickly completed. Because values are shown by positions, the abacus is very valuable in teaching arithmetic to blind students.

Experienced users operate the abacus very quickly. After World War II, a speed competition was arranged in Japan between the fastest calculator operator in the US Army and an employee of the Japanese Post Office using an abacus. The American was defeated easily by the moving beads of his opponent.

9 . Writing across Time

When students today need to take notes, they simply reach for their ballpoint pens. For students in the past, writing instruments were not so convenient.

Quill pens were made from large bird feathers. Students sharpened the quills with knives and then dipped them into pots of ink to write. The points needed constant re-sharpening and each dip of the quill provided only enough ink to write one word. Besides these problems, drops of ink often stained the page. Yet, people used quill pens for more than a thousand years. Can you imagine writing with a quill pen?

Chinese students traditionally used brush pens to practice writing characters. Unlike quill pens, brush pens had soft bristles that made smooth lines. Students dipped their brush pens in a pool of ink on an inkstone and then wrote.

In the 19th and early 20th centuries, when paper was not easily available, chalk was widely used in classrooms. Teachers wrote with chalk on blackboards while students practiced writing and maths on their own slates (石板).

Fountain pens were the first pens that stored ink inside, from where it flowed through the metal tip or nib (笔尖) for writing. In the 19th century, they finally replaced quills on school desks. However, even with fountain pens, ink still often spilt out, leaving stains everywhere.

Early ballpoint pens leaked and wrote poorly. Three inventors took almost sixty years to finally solve these problems in the early 1950s. Today two of them, Hungarian journalist Josef Laszlo Biro and French Baron Bich, are known for making the ballpoint pen cheap and reliable. Biro and Bic pens are still hugely popular and useful today.

Zhaobi, or screen walls, have a long and storied history. Zhaobi can be found outside the entrance of buildings, and in their earliest form, they     1     (build) for only the highest members of society to show their social status (地位) and protect privacy. It was believed     2     zhaobi would also act as the spiritual protection. Then they became an     3     (importance) form of artistic expression, representing good fortune appearing on the walls. Nowadays, zhaobi are still how they looked in the distant past. By evolving (演变) their function, these walls     4     (witness) China’s development, giving us a snapshot of life at a particular time in history.