Before war and time destroy more of our important cultural sites, we need to save them in 3-D digital libraries. Across 163 different countries, 1,000 natural and cultural historic places make up our most precious human heritage, which UNESCO calls World Heritage Sites.

We lose a little of that heritage every day. War, climate change and pollution have a bad effect, as do wind and rain. The $4 million a year that UNESCO spends on preservation is not nearly enough to take care of even the four dozen sites considered at approaching risk of being lost forever. Now there’s a better choice. New digital-conservation technologies let us hold on to them, at least virtually (虚拟地), through 3-D scanning, modeling and digital storage. Such projects can be accomplished (完成) through cooperation between governments, universities, industry and non-profit organizations.

To make a 3-D model, a laser (激光) scanner bounces light off an object and records the results. To reproduce every corner and opening, the scanner collects overlapping (重叠的) images from all possible angles. A computer then sews them together into one large surface image and draws lines from one point to another to create a wire-frame model. High-resolution digital cameras add color and texture. When fully put together, the models can be viewed, printed or operated.

These scans do more than preserve a memory in a database. With highly accurate measurements, archaeologists (考古学家) can find hidden passages or reveal ancient engineering tricks. School kids can explore places they might otherwise never see. And when a site is destroyed, the scans can even be used to reconstruct what was there. That has already happened for one World Heritage Site, the Kasubi Tombs in Uganda. Built of wood in 1882, they were destroyed by fire in 2010 and rebuilt in 2014, based in large part on 3-D models made in 2009. More than 100 World Heritage Sites have been already preserved as 3-D models, and conservationists are racing to record as many more as possible.

On a warm spring morning in 1984, Dong Yaohui and his two young friends pulled on backpacks and set out to hike the Great Wall. Their walk began in Shanhai Pass. 【小题1】 By sunset, they took shelter in ancient towers where soldiers once stood guard, perhaps watching for invaders from the north.

The walk of 17 months and 8,850 kilometers tested persistence. 【小题2】 The trip would not only change their lives but the fortunes of the wall itself, helping preserve it and lift it to the status it holds today.

On completing their journey, they published their experiences in a book. As they shared their adventures, it became clear that it was not just the physical demands but also the emotional impact that left lasting impressions.

【小题3】 Since then, China has made a number of measures to protect the attraction. In 2006, for instance, the State Council issued the Regulations on the Protection of the Great Wall to strengthen laws concerning its preservation and regulate activities on the structure.

The Cultural Relics Administrative Department has been given control over the overall protection of the Great Wall. 【小题4】

Dong places his hands on the weathered wall, as he did 35 years ago. But today, he thinks more deeply on a mission grander than his own journey. “Someone dug up some earth, making it into a brick,” he says. “Someone else brought it all the way up the mountain and built a wall. Then many people guarded the wall for hundreds of years. The Great Wall is definitely alive. 【小题5】”

A bronze horse head sculpture, a treasure of China’s Old Summer Palace that went missing 160 years ago, returned to its original palace home Tuesday. It is the first time that a priceless cultural artifact from the Old Summer Palace has been sent from abroad and then returned to be kept there.

Twelve animal head sculptures once formed a zodiac (生肖) water clock in Beijing’s Yuanmingyuan, built by Emperor Qianlong of the Qing Dynasty. The originals were looted (抢劫) from the royal garden by Anglo-French allied forces in 1860 during the second Opium War.

Macao billionaire Stanley Ho bought the bronze horse head and decided to donate it to the National Cultural Heritage Administration (NCHA) and return it to its original home. The NCHA has spent one year refurbishing (刷新) the old Zhengjue Temple, the main place of worship for Qing Dynasty emperors in the garden, to an exhibition venue.

An exhibition in memory of the return of the horse head has kicked off at the temple, displaying about 100 items including relics and photographs. “The horse head sculpture was returned to its original palace home amid the challenges brought by COVID-19,” said an official. “It also led to an all-round upgrade of security at the Old Summer Palace, which allows for long-term exhibitions.”

“There is international consensus (共识) on returning lost cultural relics to their original homes, and China’s efforts to bring relics home in recent years have enhanced that consensus,” he added.