breeding ground
noun
1- an area where birds, fish, or other animals habitually breed繁殖地, 产卵地。
1.1
- usu. in sing. figurative a thing that favours the development or occurrence of something〈喻〉滋生地, 发源地, 中心：
the situation is a breeding ground for political unrest.
这种局势是政治动荡的温床。