Complex sentence: The pioneers of the Nanyang Style are Liu Kang, Chen Chong Swee, Chen Wen Hsi, Cheong Soon Pieng and Georgette Chen, the first four of which had received training in traditional Chinese watercolor painting in China.
Split into simpler sentences: The pioneers of the Nanyang Style are Liu Kang, Chen Chong Swee, Chen Wen Hsi, Cheong Soon Pieng and Georgette Chen. The first four artists had received training in the traditional Chinese watercolor painting in China.