A knock can be hollow.Logical formLearned from8 sentences. A viscera can be hollow.Logical formLearned from8 sentences. Eggs can be hollow.Logical formLearned from8 sentences. Characters can be hollow.Logical formLearned from8 sentences. A wing can be hollow.Logical formLearned from8 sentences. Promises may ring hollow.Logical formLearned from8 sentences. An insistence may ring hollow.Logical formLearned from8 sentences. Assurances may ring hollow.Logical formLearned from8 sentences. An affair can be hollow.Logical formLearned from8 sentences. Rings can be hollow.Logical formLearned from8 sentences. (Chocolate eggs) can be hollow.Logical formLearned from7 sentences. Limbs can be hollow.Logical formLearned from7 sentences. (Box girders) can be hollow.Logical formLearned from7 sentences. A bronze can be hollow.Logical formLearned from7 sentences. A monument can be hollow.Logical formLearned from7 sentences.