A virus may trigger a pandemic.Logical formLearned from12 sentences. A male may isolate a virus.Logical formLearned from12 sentences. A woman may succumb to a virus.Logical formLearned from12 sentences. A country may discover a virus.Logical formLearned from12 sentences. A virus may cause symptoms.Logical formLearned from12 sentences. A boy may contract a virus.Logical formLearned from12 sentences. A (bird flu virus) may be detected in a country.Logical formLearned from12 sentences. An advance may pertain-to a virus.Logical formLearned from12 sentences. A culprit can be a virus.Logical formLearned from12 sentences. An outbreak of (bird flu) can be a strain of a virus.Logical formLearned from12 sentences. A (bird flu virus) may spark a pandemic.Logical formLearned from12 sentences. Some nations may report a resurgence of a virus.Logical formLearned from12 sentences. A resurgence may pertain-to a (killer virus).Logical formLearned from12 sentences. Access can be to viruses.Logical formLearned from12 sentences. A virus may undergo an explosion.Logical formLearned from12 sentences.