For instance, with worsening environmental pollution, there is growing research interest in "indicator species," which can indicate the severity of pollution. These include frogs, which have very different larval and adult forms, and can live both on land and in water.
今日大環境汙染越嚴重，可以反映環境汙染程度的「指標物種」，例如具有兩種生活型態，可生存水中與陸地的青蛙，就越來越引起研究人員的興趣。