Archaeologist and author Liu Yiman has not let retirement douse a passion for her favorite subject.
History teachers come in at least two varieties: those whose lessons are so fascinating that students are keen to flip open their textbooks to find out more; and those whose lessons are as dry as old bones, so much so that students turn their back on history the minute they leave school.
Liu Yiman can count herself as a lucky woman, someone who had a very compelling teacher of history, and yet managed to end up holding dry bones, ones that have kept her captivated for more than 50 years.
The bones Liu has worked with in Anyang, Henan province, for all those years are very special－oracle bones that have told us so much about Chinese history stretching back thousands of years.
"Curiosity about the past is my passion," Liu says.
Liu, 81, was an archaeologist with the Chinese Academy of Social Sciences before she retired at the age of 65 in 2005.
"My interest in history began in middle school because my history teacher always gave such vivid classes," she says.
However, Liu found the idea of reading archives and documents in a dimly lit library for the rest of her life difficult to countenance.
"I was restless, and I liked things like traveling and sailing, so the kind of research that appealed to me was history in the field."
In the 1950s, archaeology as a main subject was a rarity in Chinese universities, so the Guangdong native went to study at Peking University. That was in 1956.
Liu's first fieldwork, during her second year, was in Zhoukoudian, in Beijing's Fangshan district.
"At the time, few people majored in archaeology, and there were just 24 students in our class. In those days, we used fireworks to crack stones to speed up digging work, something that would be considered inappropriate now."
The inscribed oracle bones were first unearthed in China in Anyang in 1899. The inscriptions, which academics regard as the origin of Chinese characters, are highly revelatory, especially in understanding the lives of royal and elite families, including their habits with regard to hunting, ancestral worship and medical treatment.
Among archaeologists Anyang is almost regarded as sacred ground, so it was highly attractive to Liu, who applied to work there in 1972.
"Many kinds of artifacts were unearthed in Anyang, such as pottery and bronze. But I was attracted by oracle bones and the inscriptions on them."
Liu has taken part in the last two of the three major archaeological discoveries related to oracle bones in China over the past decades.
In December 1972, a local farmer found a few pieces of oracle tortoise shells by the road while doing farm work in Xiaotun village in Anyang, and sought out Liu to identify them.
"The finding was an absolute fluke, and it was too cold to start the digging right away," Liu says.
In 1973 between March and August, and again between October and December, more than 3,000 bone specimens were excavated, among which more than 1,200 had inscriptions.
The other big archaeological find in which Liu took part was in 1991 in Huayuanzhuang village, not far from Xiaotun. There, 1,583 oracle bone specimens were excavated, 689 with inscriptions. Liu remembers the exact numbers.
"Unlike the ones found in 1973, which record mainly the activities of the emperor, the ones found in 1991 record the activities of the royal family," Liu says.
"The bones are key to studying the history of the Shang Dynasty (c.16th century-11th century BC).
"With the help of technical workers, we cleaned the bones, took pictures of every single piece, put together small specimens, replicated the shape of every bone and the inscriptions, made cards for each character and gave a serial number to the bone upon which it appears."
In the 1990s, most of the work was done manually.
"For archaeologists of oracle bones, patience and care are essential."