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hotbed; breeding ground
不衛生な環境は病気の温床となりやすい。
An unsanitary environment easily becomes a breeding ground for disease.
汚職の温床を根絶するための改革が必要だ。
Reform is needed to eradicate the breeding ground of corruption.
温床で育てた苗を畑に植え替える時期が来た。
The time has come to transplant the seedlings raised in the hotbed to the field.