The pollution had destroyed ozone layer and caused many changes in weather.
污染破坏了臭氧层, 并引起了许多天气变化。
pollution of the water supply reached a level pernicious to the health of the population.
水源污染已经达到危及居民健康的程度。
pollution poses a threat to the continued existence of this species.
污染对这一物种的继续生存造成了威胁。
