Volcanic ash may hang over a continent.Logical formLearned from3 sentences. A volcanic eruption may interfere with an effort.Logical formLearned from3 sentences. An airspace may be threatened by volcanic ash.Logical formLearned from3 sentences. An (airline chaos) may be caused by a volcanic eruption.Logical formLearned from3 sentences. Pilots may have of volcanic ash.Logical formLearned from3 sentences. A volcanic plume may cover an area of (air traffic).Logical formLearned from3 sentences. A volcanic ash can be high-altitude.Logical formLearned from3 sentences. Some percent of a volcanic activity may occur in a sea.Logical formLearned from3 sentences. A volcanic eruption can be deep-sea.Logical formLearned from3 sentences. A volcanic island may become a casualty of a global economic crisis.Logical formLearned from3 sentences. A plume of volcanic ash may rise some feet.Logical formLearned from3 sentences. A (ridge line) can be volcanic.Logical formLearned from3 sentences. A town may be destroyed by a volcanic eruption.Logical formLearned from3 sentences. Hills may be made fertile by volcanic soil.Logical formLearned from3 sentences. A lake may be formed by a volcanic crater.Logical formLearned from3 sentences.