Chinese President Xi Jinping has used a rare event marking the birth centenary of former leader Jiang Zemin to reflect on China's past and its path ahead. Drawing on Jiang's legacy of reform, opening up and innovation, Mr Xi linked it to China's priorities as Beijing faces economic and geopolitical challenges. The Chinese Communist Party is holding its Fifth Plenum later this year, ahead of a five-yearly Party Congress and an expected leadership reshuffle next year. Tan Si Hui reports from Beijing.