【推荐1】We usually think of archaeology as involving brave explorers and lots of painstaking digging. But today, long-hidden cities are being revealed from the air, where modern archaeologists use laser beams to spot evidence of ancient life buried beneath thick vegetation.

Lidar, short for “light detection and ranging” (and a cousin of radio-based radar), involves directing a rapid succession of laser pulses at the ground from an airplane or a drone. Software captures the time and wavelength of the pulses reflected from the surface and combines it with GPS and other data to produce a precise three-dimensional map of the landscape below. These high-tech explorations have revealed long-buried Mayan cities.

In recent years, lidar has exposed a sprawling ancient city in western Mexico called Angamuco, The discovery of this long-lost Mexican large city is especially significant. Built by the Pur pecha, Angamuco was a major civilization in the early 16^th century, before Europeans arrived. The city extended over ten square miles before it was covered by a lava flow. That is a huge area with a lot of people. There are about 40, 000 building foundations there, which is about the same number of building foundations that are on the island of Manhattan. The Pur pecha’s main buildings were loosely sited in eight zones around the edges rather than being located in one large center.

“To think that this massive city existed in the heartland of Mexico for all this time and nobody knew it was there is amazing,” says Chris Fisher, an archaeologist who led the expedition.

The revelation of Angamuco is a prime example of the power and promise of lidar. Archaeologists discovered signs of the buried city in 2007 and initially attempted to explore it using a traditional “boots on the ground” approach. But the team soon realized that with the rugged terrain, it would take at least a decade to outline the entire massive city.

In 2011, they began using lidar to map nearly 14 square miles, revealing many astonishing features, from pyramids and temples to road systems, garden areas, and even ball courts. This gave them the “map” they needed to know where to explore further. So far, Fisher and his team have verified more than 7,000 architectural features over a 1.5-square-mile area. The earliest artifacts include ceramic fragments and other remains dating as far back as AD 900.

All told, researchers now believe that more than 100, 000 people lived in Angamuco from about AD 1000 to AD 1350. That makes it the biggest city in western Mexico at the time-or at least the biggest city we know about so far.

“Everywhere you point the lidar instrument, you find new stuff,” says Fisher. “Right now, every textbook has to be rewritten, and two years from now, they’re going to have to be rewritten again.”

【推荐2】Chinese archaeologists (考古学家) announced on Saturday that some new major discoveries have been made at the Sanxingdui Ruins site in Southwest China, helping uncover another start of the Chinese civilization.

Archaeologists have found six new sacrificial pits (祭祀坑) and unearthed more than 500 treasures dating back 3,000 years at the Sanxingdui Ruins in Sichuan Province. So far, archaeologists have unearthed masses of important cultural items from four of the pits, including pieces of gold masks, gold foil, bronze (青铜) masks, bronze trees and large numbers of ivories. The rest of the newly discovered pits are still being dug up.

“Surprisingly, we have unearthed some never-heard-of-before bronze items,”said Lei Yu, from the Sichuan Archaeology Research Institute. “For instance, some large and well-made bronze items have strange-looking dragon or cow designs on them.”

In another major discovery, relics of silk products were found for the first time at Sanxingdui, which shows “the ancient Shu Kingdom was one of the important starts of silk in ancient China” according to Tang Fei, head of the digging team.

The new pits sit next to two sacrificial pits discovered in 1986, with areas ranging between 30 square meters and 19 square meters. Together they form an area in which people of the ancient Shu civilization held ceremonies to offer sacrifices to heaven, earth and their forefathers, and prayed for good luck and peace.

The Sanxingdui Ruins is regarded as one of the greatest archaeological finds of mankind in the 20th century. The site was accidentally discovered by a farmer in the 1920s. The ruins are located in the city of Guanghan, about 60 kilometers from Chengdu and are believed to be the relics of the Shu Kingdom.

【推荐3】Switzerland(瑞士) is famous for its watches. However, this country didn’t invent the watch.It was the British who did it. Here is a story of how the watch was brought to Switzerland.

Many years ago , an Englishman was travelling to Italy . On his way he stopped in a small town in South Switzerland. This Englishman travelled in a carriage(马车) inside which there was a carriage watch. This was the earliest kind of watch. A native shop assistant (售货员) happened to see the watch . He wondered what it was and asked the Englishman about it. “ It is a carriage watch .” said the man . This machine tells the time but now it isn’t working .

At once the shop assistant offered to try to repair it . So the traveller handed him the watch. The assistant was a very wise man . So it was not surprising that he managed to repair it . He even remembered how it was made. As soon as the traveller had gone on his way , he made a watch exactly the same type.

Thus the watch-making was started in Switzerland. Today Swiss watches are sold in stores all over the world.