A ceasefire is to take effect Saturday in eastern Ukraine. The ceasefire agreement came this week after all-night talks involving the leaders of Ukraine, Russia, France and Germany. Yet the leaders admit many details are yet to be worked out. Diplomats add that the agreement left many disputes unresolved. ______________________________乌克兰东部停火协议于星期六生效.这项停火协议是由乌克兰,俄国,法国和德国的领导人彻夜谈判,本周出台的.然而领导人们承认许多细节还有待商讨.外交官补充说到,这项协议留下了许多尚未解决的争端.________________________