2 . About 5,300 years ago, people from the grasslands of modern-day Russia and Ukraine expanded rapidly across Eurasia. Within a few centuries these “Yamnaya” left a lasting genetic mark on populations from central Europe to the Caspian Sea. Today, archaeologists call them “eastern cowboys” for their livestock herding (畜牧) and highly mobile lifestyle.

But one part of the classic cowboy picture was missing: horseback riding. Although cattle bones and solid carriages have been found in Yamnaya sites, horse bones are hard to find, and most archaeologists assumed people did not start to ride horses until at least 1,000 years later.

In a new study published in Science Advances, researchers say they’ve found the earliest evidence of horseback riding not in the bones of ancient horses, but in their Yamnaya riders. “Everyone has focused on horse remains to get an idea of early horse riding,” says co-author and University of Helsinki archaeologist Volker Heyd. “Our approach was to look at humans.”

The researchers looked at more than 150 bones unearthed in Romania, Hungary, and Bulgaria — the western frontier of Yamnaya expansion. The Yamnaya were well-fed, healthy, and tall; the chemical composition of their bones showed protein rich diets consistent with herding cattle and sheep. But the bones showed signs of distinctive wear and tear. They also showed thick spots on the leg bone consistent with lots of time spent on the horse back. Healed injuries matched the kinds of damage a kicking horse might cause, or what sports medicine doctors today see in riders thrown from their horses.

“In terms of trying to identify people riding horses, I think they’ve done the best job possible bioarchaeologically,” says bioarchaeologist Jane Buikstra. “That doesn’t mean it’s perfect, or convincing, ultimately.”

More samples — including horse bones with signs of riding, such as bit marks or back bone damage from the weight of a rider — would help make the case, says CU bioarchaeologist Lauren Hosek. What the group has found “is really interesting”, she says. “But there’s a lot more work to be done when the risks of drawing the final conclusion are as high as the earliest horse riding.”

A great number of artifacts from eight tombs    1     (unearth) from an archaeological site in Hunan province several months ago. According to the provincial institute of heritage and archaeology, these artifacts, including pottery pieces and bronze    2     (knife), are believed    3     (date) back as early as the Eastern Han Dynasty (25-220).

Six Eastern Han Dynasty tombs are brick tombs, three of    4     might have had owners from the same family, said Chen Bin,     5     member of the archaeological team of the tomb complex under the institute.

It is also the first time that archaeologists    6    (discover)a trench(战壕)4.5meters west of the back chamber of the largest tomb,     7     (measure) about 0.9 meters in width,     8     (approximate)15 meters in length and about 0.1 meters in depth.

“This excavation(挖掘)is    9     great significance to further understanding the funeral customs of people in southern Hunan, as well as the levels of    10     (economy)development and cultural exchanges during the period,” Chen said.

5 . Scientists have solved a puzzle about modern humans, after research showed that a famous skull of a human ancestor found in South Africa is a million years older than experts thought. This discovery has changed what we know of human history.

The skull, which scientists have named “Mrs Ples”, is from an ape-like human relative from a species called Australopithecus africanus (南方古猿). It was found near Johannesburg in 1947 and, based on evidence from its surroundings, was thought to be between 2. 1 and 2. 6 million years old. This puzzled scientists, because although Mrs Ples looks like a possible early ancestor of early humans, the first true humans had already evolved by the time she apparently lived. For this reason, scientists had decided that Australopithecus afarensis, a similar species from East Africa that lived about 3.5 million years ago, was our most likely ancestor instead.

To get a more accurate age for Mrs Ples, a team led by Professor Darryl Granger of Purdue University in Indiana, US, used a new method to date the sandy rocks where the skull lay. They measured the amount of certain chemicals in rocks, which form at a steady rate when they are exposed to cosmic rays (宇宙射线) on Earth’s surface. Once rocks are buried, these chemicals stop forming and slowly disappear;the surviving amount reveals how much time has passed since the rock (or bones) were on the surface.

The new study shows that Mrs Ples and other australopithecine bones nearby are between 3.4 and 3.7 million years old. This means they lived at the same time as their East African relatives, so that either group could have given rise to modern humans. However, team member Dr Laurent Bruxelles pointed out that over millions of years, at only 2,500 miles away, these groups had plenty of time to travel and to breed with each other. In other words, the groups could quite easily have met, had children together and both been part of the history of modern humans.

What’s in a name?

According to the British history, Wales is the first country to be joined to the Kingdom of England, which happened in the 16^th century. Later, Scotland and Ireland     1     (add) to create the United Kingdom of Great Britain and Ireland     2    (break) away from the UK, which resulted in the full name we have today: the United Kingdom of Great Britain and Northern Ireland, whose     3     (shorten) name is “the United Kingdom” or “the UK”. The four countries of the UK use the same flag as well as the same currency and military defense. However, they also have some differences, like different legal systems. The UK’s long and interesting history can help you understand much more about the country and its traditions. Studying the history of the UK will make your visit much more     4     (enjoy). The capital city London is a great place to start, as it is an ancient port city that has a history     5     (date) all the way back to Roman times. There are countless historic sites to explore, and lots of museums with ancient relics from all over the UK.

    1     (know) a little bit about British history will help you solve this puzzle. In the 20th century, the southern part of Ireland broke away     2     the UK, which resulted     3     the full name we have today. Most people just use the     4     (shorten) name: “the United Kingdom” or “the UK”. Studying the history of the country will make your visit much more     5     (enjoy).