But in the early 1970s, two chemists, mario Malina and Sherwood Roland, demonstrated that widely used chemicals called chlorophoral carbons, or cfcs, could upset this balance.

但在20世纪70年代初 两位化学家马里奥·马里纳(marioMalina)和舍伍德·罗兰(SherwoodRoland)证明 被广泛使用的化学物质氯氟烃(cfcs)可能会破坏这种平衡。