 Complete the following phrase:  Based in Beijing, Liu began to establish himself at national level in his early twenties. A personal best of in 1990 was followed by an improvement to in 1992  a mark which ranked him second at the Chinese Athletics Championships to Ma Yongfeng and placed him within the top 100 globally that year. He had his breakthrough on the international scene the following year. He progressively improved his best over the 1993 season, culminating in a lifetime best throw of to win the title at the 7th National Games of China. After this first victory at national level, he was selected for the 