natural focus

• 自然疫源地(动)

natural focus的用法和样例：

例句

1. Conclutions The virulence of Y.pestis from plague nature foci is moderate.
   结论河北省鼠疫自然疫源地病原菌毒力属于中等毒力。
2. As one of the oldest identifiable diseases known to man, plague remains endemic in many natural loci around the world.
   鼠疫作为人所共知的一种最古老可确定的疾病，在世界上许多自然疫源地仍呈地方性流行。