But a scarcity of commodities was sweeping across the country after Stalin's death, and the educational authority of the Soviet Union (SU) soon decided to put all overseas students in Moscow, where the scarcity was less severe.
Sun joined the Moscow Geological Institute and found 20 other Chinese students there. In her class were 23 students from SU states, seven Chinese, one North Korean, one German, one Mongolian, one Vietnamese and one Albanian.
The Chinese students studied hard. "We believed our expertise would be needed everywhere," says Sun. They were also encouraged by the 156 major projects which the SU promised in 1953 and 1954 to help China build in the next five years, and expected to work for these after graduation.
The relationship between young people from different countries of Communism International was "very nice and pure," according to Sun. It was unaffected by the subtle changes in relations between China and SU after 1956, and some Chinese even fell in love with their foreign classmates, which was forbidden at the time.
When the SU celebrated the 40th anniversary of the 1917 Revolution, which led to its founding, Communist leaders of more than 40 countries got together in Moscow and Mao Zedong arrived with a Chinese delegation in 1957. A convention was held at the Lenin Stadium and joined by 30,000 people. Song Qingling, then vice-chairman of China, gave an optimistic speech about bilateral relations.
One evening, Mao met the Chinese students and gave a speech which was repeatedly quoted throughout his era, especially during the "cultural revolution" (1966-76). "The world is yours and also ours, but in the end it is yours," he said. "The young people are filled with vitality, like the sun at eight or nine in the morning."
The first group of Chinese students, numbering more than 800, graduated in 1959 and was welcomed by Liu Shaoqi, then vice-chairman of China, and Premier Zhou Enlai when they returned. They became engineers, officials and professors, and remained in contact with their foreign friends until 1962, when it was ordered that all contacts with the SU be cut off.
Some of them were tortured during the "cultural revolution", and those who courageously brought back their foreign lovers suffered from the breakup of families. Luckily, Sun escaped physical abuses although she was attacked in big-character posters.
When China re-opened its doors to the rest of the world and contacts were re-built between former classmates, Sun's foreign classmates were thrilled because they believed their Chinese friends would have died during the ten-year turmoil.
Sun spent one year at Moscow University as a visiting professor in 1991, and
upon her arrival 13 of her friends flew from around Europe to give a welcome
party. In 2000, she and two of her Chinese classmates took their families to
Moscow, hoping this friendship could be continued by the younger generations.