hotbed
/ˈhɒtbed/noun
1- a bed of earth heated by fermenting manure, for raising or forcing plants（由发酵的粪肥产生热量的）温床（为栽培植物或促使植物生长）。
1.1
- an environment promoting the growth of something, especially something unwelcome（促使某事物发展的环境, 尤指不受欢迎之物）温床：
the country was a hotbed of revolt and dissension.
该国是反叛和冲突的温床。