試題詳解

76. According to the passage, which of the following is true about human-generated air pollution in localized regions?
(A) It can be dwarfed by nature's output of pollutants in the localized region.
(B) It can overwhelm the natural system that removes pollutants.
(C) It will damage areas outside of the localized regions.
(D) It will react harmfully with naturally occurring pollutants.