61.   And winter conditions make military operations difficult in the mountainous terrain.

62.   An effective buffer zone there is a difficult proposition given the mountainous terrain.

63.   As the bombing went on, Taliban and opposition fighters exchanged artillery and gun fire from their positions in the mountainous terrain.

64.   But each time the troops leave, the guerrillas return to the mountainous terrain.

65.   But each time troops leave, guerrillas return to the mountainous terrain.

66.   But ethnic Albanians and international aid officials spoke Tuesday of shelling that forced entire villages to hike through mountainous terrain to neighboring Albania.

67.   But darkness and the mountainous terrain were likely to hinder rescue and recovery efforts until dawn.

68.   But the darkness and the mountainous terrain was likely to hinder search efforts until dawn.

69.   But snow began to fall again later in the morning, making progress over the mountainous terrain difficult, Armagan said.

70.   Cellular telephone calls sometimes fail in West Virginia because the mountainous terrain blocks radio signals.