An infrastructure can be gray.Logical formLearned from22 sentences. A strip can be gray.Logical formLearned from22 sentences. A gray whale may undergo a killing.Logical formLearned from22 sentences. An issue can be gray.Logical formLearned from22 sentences. A person may have gray hairs.Logical formLearned from22 sentences. Power can be gray.Logical formLearned from22 sentences. Silver can be gray.Logical formLearned from22 sentences. A (prison uniform) can be gray.Logical formLearned from22 sentences. (Apartment blocks) can be gray.Logical formLearned from22 sentences. Persons can be in a gray area.Logical formLearned from22 sentences. A curtain can be gray.Logical formLearned from22 sentences. A fur can be gray.Logical formLearned from21 sentences. Backs can be gray.Logical formLearned from21 sentences. Mornings can be gray.Logical formLearned from21 sentences. Years can be gray.Logical formLearned from21 sentences.