(Cement walls) can be gray.Logical formLearned from15 sentences. Gray whales may undergo a migration.Logical formLearned from15 sentences. A coffin can be gray.Logical formLearned from15 sentences. A mineral can be gray.Logical formLearned from15 sentences. A center can be gray.Logical formLearned from15 sentences. A covering can be gray.Logical formLearned from15 sentences. A (ground color) can be gray.Logical formLearned from15 sentences. Chairs can be gray.Logical formLearned from15 sentences. A facade can be gray.Logical formLearned from15 sentences. A man can be with gray eyes.Logical formLearned from15 sentences. Persons can be with gray hair.Logical formLearned from15 sentences. A light can be gray.Logical formLearned from15 sentences. An airlifter can be gray.Logical formLearned from15 sentences. A (sea salt) can be gray.Logical formLearned from15 sentences. (Cargo pants) can be gray.Logical formLearned from15 sentences.