To improve a high schoolers chance of getting into a top university, the summer programs allow young students to explore fields of interest and get a taste of college life.

Telluride Association Summer Program (TASP)

TASP is a six-week program allowing high school freshman from around the world to grow their sense of interpersonal awareness and community responsibility. It's completely free, including the cost of tuition, books and even travel.

Minority Introduction to Engineering and Science (MITES)

This week-long program aimed at all US high school students can help them develop the skills necessary for future job in engineering while learning about the value and reward of acquiring advanced technical degrees. MITES is free—the only expense is the transportation to and from MIT.

Clark Scholar Program (CSP)

High school students coming from across the globe are offered the unique opportunity to gain hands-on research experience in mathematics field while working one on one with teaching staff over four intense weeks. Everything is free for chosen applicants except their meals.

JCamp

The seven-week one brings high school freshman and sophomores from various backgrounds together for participating in sessions and workshops led by notable journalists where students can get hands-on training in journalism. JCamp is free if selected-participants only need to pay for the board.

Tombs dating back to 4th century discovered in Shaanxi Province

（文章来源：Global Times）

A cemetery with 285 tombs dating back to the 4th century has been unearthed in Northwest China's Shaanxi Province, reported the state broadcaster CCTV on Wednesday, citing the Xi'an Institute of Cul-tural Relics and Archaeology. The discovery not only sheds light on the evolution of the burial and sacrifi-cial system in ancient times, but also contributes to studies on population mixing and ethnic integration.

The tombs, which span a time from the Sixteen Kingdoms period (304-439) to the Sui and Tang dynasties (581-907), were found in an orderly aligned layout. The cemetery stands as the largest independent cemetery from the period found to date. 

All the tombs in the cemetery are oriented toward the east. This practice was consistently maintained from the early years of the Sixteen Kingdoms to the Tang Dynasty, spanning over 300 years. Archaeologists say this demonstrates strong uniqueness and stability.

The find also represents a crucial link in the evolution of ancient Chinese burial practices, showcasing a unique blend of burial systems spanning from the independent mausoleum traditions of the Warring States period to the family cemetery systems of the Northern Dynasties (439-581) and Sui and Tang dynasties, according to the report. Archaeologists say the excavation of the graveyard helps shed light on the evolution of the burial and sacrificial system in northern China in the Sixteen Kingdoms period and Northern Dynasties. In addition, pottery figurines, pottery stoves and kettles, pottery lanterns and epitaph bricks imprinted with characters identifying the year the brick was made were unearthed from the tombs.

The evolving burial styles and accompanying artifacts within the cemetery suggest a cultural synthesis. The inhabitants of this cemetery adhered to their ethnic traditions while adapting elements of Han Chinese culture. This reflects the gradual integration of ethnic minorities who migrated to the Central Plains during the Sixteen Kingdoms and Northern Dynasties period, providing valuable insights into the complex historical and cultural dynamics of the Chang'an (the old name for Xi'an and capital of the Tang Dynasty) region over the 300 years spanning the Northern Dynasties and the Sui and Tang. 

The discovery will also contribute to studies on population mixing and ethnic integration in the Chang'an area, serving as an important manifestation of the characteristics of Chinese civilization, emphasizing "inclusive integration and unity in diversity," according to the report.

"Inspector Sands to the control room, please." If you ever hear that at a British train station, don't panic. But you might appreciate knowing that this is a codeword meant to inform staff that there is an emergency somewhere in the building. The idea is to avoid causing alarm among commuters (通勤者), but still get the message out to those trained to deal with the problem.

The subject of secret codewords like this was raised this week on Reddit, and the discussion has attracted thousands of examples. But what codewords and signs are really out there in the wild?

A good place to start is hospital emergency codes. These are often colour-coded, and one health centre in Canada has published its list online. "Code red" announces a fire, "code white" indicates a violent person while "code black" means a bomb threat is active. It's been reported that hospital staff sometimes refer to the morgue as "Rose Cottage", in order to avoid upsetting relatives of a patient who has recently died.

"I can see very good reasons for having these codes," says Paul Baker, a linguist at the University of Lancaster. "It may be that people are unsure when they're giving the code so there's no point upsetting members of the public."

Not all codes are alphanumeric (字母数字的). Some are visual, intended to be hidden in plain sight. As BBC Future discovered earlier this year, many banknotes feature a specific pattern of dots placed there to prevent people from photocopying money. Many copiers and scanners are programmed to spot it.

And finally, the spray-painted squiggles (波形曲线) you see on pavements in towns and cities all over the world are codes understood by construction workers and engineers. For example, in UK, different colours are related to different types of cable or pipe. Blue meant a water system while yellow indicated gas lines and green labelled CCTV or data wiring.

All of these codes have a purpose — to avoid causing panic, to transmit subtle signals in social groups, or to provide technical information quickly and easily. "People don't like secrets, do they?" says Baker. "There is a drive to have as much information as possible — we do live in the information age," he adds.