Reptiles can be harmful.Logical formLearned from1 sentences. Some insects can be harmful to persons.Logical formLearned from1 sentences. A use of troops can be harmful to relations.Logical formLearned from1 sentences. (Invader cells) can be harmful.Logical formLearned from1 sentences. (Combustion gases) can be harmful.Logical formLearned from1 sentences. Some (ground beetles) may be considered harmful.Logical formLearned from1 sentences. (Gene mutations) can be harmful to organisms.Logical formLearned from1 sentences. Gastropods can be harmful.Logical formLearned from1 sentences. (Heat rays) can be harmful.Logical formLearned from1 sentences. Life-styles can be harmful.Logical formLearned from1 sentences. Concentration of power can be harmful.Logical formLearned from1 sentences.