Youth may be infected.Logical formLearned from2 sentences. A disease may infect some percent of a population.Logical formLearned from2 sentences. Some persons may be infected with pylori.Logical formLearned from2 sentences. Half of individuals may be infected.Logical formLearned from2 sentences. Plants may be infected with (aster yellows).Logical formLearned from2 sentences. Persons may be infected by drinking water.Logical formLearned from2 sentences. Someone may be infected with a virus.Logical formLearned from2 sentences. A virus may infect chipmunks.Logical formLearned from2 sentences. An average of some percent of trees may be infected across a range.Logical formLearned from2 sentences. A cat may be infected with a virus.Logical formLearned from2 sentences. A machine may be infected by a virus.Logical formLearned from2 sentences. Children may be infected with varicella.Logical formLearned from2 sentences. Some children may be infected with a human (immunodeficiency virus).Logical formLearned from2 sentences. A virus may infect some percent of persons.Logical formLearned from2 sentences. An animal may be infected with virus.Logical formLearned from2 sentences.