I want to introduce a beautiful coastal city-Sanya which is located in southern area of Hainan province. 2.我介绍完三亚后 我想说欢迎到三亚旅游的意思 是不是可以说welcome to sanya
改为 I want to introduce a beautiful coastal city,(这里不用破折号)Sanya, (非限定性定语从句加个逗号,后面的is去掉) which located in the (地点特指,加个冠词) southern area of Hainan province.