The virus was first identified in 1931 during an investigation into an epidemic among sheep on a farm in the Rift Valley of Kenya.
该病毒最早于1931年确定,当时正在对肯尼亚里夫特山谷一农庄羊群中的一种流行病进行调查。
It「s very easy to show if you live on a farm or keep a dog, you」re less likely to have these disorders. If you are the youngest child in a big family, you「re less likely to have these disorders.