A piano can be hollow.Logical formLearned from2 sentences. Holds can be hollow.Logical formLearned from2 sentences. A compliment can be hollow.Logical formLearned from2 sentences. A stems can be hollow.Logical formLearned from2 sentences. (Agony parents) can be hollow.Logical formLearned from2 sentences. A (rubber toy) can be hollow.Logical formLearned from2 sentences. An accusation can be hollow.Logical formLearned from2 sentences. Recitations can be hollow.Logical formLearned from2 sentences. Democracy may remain hollow.Logical formLearned from2 sentences. A rattle can be hollow.Logical formLearned from2 sentences. Roles can be hollow.Logical formLearned from2 sentences. (Stone ruins) can be hollow.Logical formLearned from2 sentences. A reflection can be hollow.Logical formLearned from2 sentences. A commitment can be hollow.Logical formLearned from2 sentences. A concrete island can be hollow.Logical formLearned from2 sentences.