The United States officials say the US and Cuba have reached a deal to reopen embassies in Washington and Havana. The deal is a major milestone in a process which began with secret negotiations and took off last December when both presidents announced a thaw in relations._________________________ 美国官方表示,美国和古巴已经达成协议重新开启两国在对方的大使馆.该协议是一个重大里程碑.该进程以秘密谈判开始,于去年12月成功,两国总统宣布邦交解冻.________________