原标题：中方开出对话条件，美军司令呼吁回归一中政策，奥斯汀在仁爱礁部署特遣队
The 19th Group of Twenty (G20) Summit was held in Rio de Janeiro Brazil from Monday to Tuesday. In the face of geopolitical conflicts and economic uncertainties, the G20 Summit is expected to exert positive impacts and inject more stability into an unstable world, said Cui Shoujun, Professor and Director of the Institute of International Development Studies at the School of International Studies, Renmin University of China (RUC), in the W.E. Talk with China News Network.