HONG KONG (Reuters) - For his last class in Hong Kong in July, liberal studies teacher Fong showed his students calligraphy by the territory's late democratic activist Szeto Wah: "Choose the right path and stick to it." He emigrated to Britain days later.... ... Grace Kwok, a 33-year-old music teacher who moved to Britain in January...told Reuters some parents complained to her principal after she told pupils that Tian Han, who wrote the lyrics of China's national anthem, "March of the Volunteers," died in prison during Mao Zedong's 1960s Cultural Revolution.... ...In February, Hong Kong introduced new curriculum guidelines ensuring...