一个藏族孩子告诉我苍蝇这种东西以前拉萨是没有的?真的吗?

一个藏族孩子告诉我苍蝇这种东西以前拉萨是没有的?真的吗?

有人的地方就有苍蝇,不是谁从什么地方带过来的。http://entnemdept.ufl.edu/creatures/urban/flies/house_fly.htm“This common fly originated on the steppes of central Asia, but now occurs on all inhabited continents, in all climates from tropical to temperate, and in a variety of environments ranging from rural to urban. It is commonly associated with animal feces, but has adapted well to feeding on garbage, so it is abundant almost anywhere people live.”之所以会有这种言论,除了别有用心破坏民族团结的因素之外,可能是因为随着交流和开发,城市逐步发展,人口密度增大,卫生设施没有同步建设。要想举个吐槽的反例很简单,北京CBD写字楼里汉族人特多,苍蝇真不多。
麻烦采纳，谢谢!