Influenza may be caused by viruses.Logical formLearned from12 sentences. Viruses may be isolated.Logical formLearned from12 sentences. A virus may be made.Logical formLearned from12 sentences. Isolates may pertain-to a virus.Logical formLearned from12 sentences. An amount of virus may drop.Logical formLearned from12 sentences. A virus may belong to a family.Logical formLearned from12 sentences. A percent may pertain-to a virus.Logical formLearned from12 sentences. A virus may spread across a globe.Logical formLearned from12 sentences. A transmissibility may pertain-to a virus.Logical formLearned from12 sentences. A version may pertain-to a (flu virus).Logical formLearned from12 sentences. A cold virus can be modified.Logical formLearned from12 sentences. Virus may be carried by mosquitoes.Logical formLearned from12 sentences. A (flu virus) can be mysterious.Logical formLearned from12 sentences. (Virus levels) can be low.Logical formLearned from12 sentences. Subtypes may pertain-to a virus.Logical formLearned from12 sentences.