Most of the cases have been confined to the Yangtze River delta region.

大多数确诊病例分布在长三角地区。

The navy helicopter, which was on its way to Port Harcourt, came down in Bayelsa State in the oil-rich southern delta region.

这架海军直升机当时正飞往哈科特港，在石油重镇的南部三角洲巴耶尔萨州坠落。