51.   A Department of Energy team works capping old wells and cleaning up environmental damage.

52.   A parade of conference speakers from Florida to Alaska warned of environmental damage from pipeline spills and unseen leaks.

53.   Airline officials insisted that the dumped fuel evaporated at high altitude and caused neither environmental damage nor flying hazards.

54.   But besides the environmental damage, oil spills pose major economic costs to industry in cleanup expense and lost product, said Greco of the petroleum institute.

55.   But Congress blocked a similar American project over concerns about economic feasibility and possible environmental damage.

56.   But Fox also hopes for more American coordination on fighting drugs, and on cleaning up environmental damage along the border.

57.   But in most nations base agreements are decades old, signed long before anyone paid attention to environmental damage.

58.   But Pouyat argued that the science of measuring acid rain and determining how much environmental damage it is causing has improved dramatically in the last seven years.

59.   But some scientists argue that engineering nature to avoid environmental damage inevitably causes other, perhaps greater damage.

60.   But some scientists argue that engineering nature to avoid environmental damage inevitably causes other, perhaps greater, damage.