Youths may wear black masks.Logical formLearned from12 sentences. A person may come_up with an (oxygen mask).Logical formLearned from12 sentences. Miners may have (oxygen masks).Logical formLearned from12 sentences. Some persons may wear surgical masks.Logical formLearned from12 sentences. Masks can be bright.Logical formLearned from12 sentences. (Health workers) may wear (face masks).Logical formLearned from12 sentences. (Ground crews) may wear (face masks).Logical formLearned from12 sentences. Surgical masks can be dirty.Logical formLearned from12 sentences. Gunmen can be in (ski masks).Logical formLearned from12 sentences. Masks can be stuffy.Logical formLearned from12 sentences. Police may wear masks.Logical formLearned from12 sentences. Masks can be effective.Logical formLearned from12 sentences. Firefighters can be with masks.Logical formLearned from12 sentences. A (trademark ski mask) may pertain-to a male.Logical formLearned from12 sentences. (Gas masks) can be makeshift.Logical formLearned from12 sentences.