In the event of a blockade of its trade routes, for instance, South Africa has filled disused mine shafts with enough crude oil to provide the nation with at least two years' worth of petroleum.

例如，在其贸易路线遭到封锁的情况下，南非已经用足够的原油填充了废弃的矿井， 足以为该国提供至少两年的石油。