A vale can be hollow.Logical formLearned from8 sentences. Nanospheres can be hollow.Logical formLearned from8 sentences. A top can be hollow.Logical formLearned from8 sentences. Nanocrystals can be hollow.Logical formLearned from8 sentences. An optical fiber can be hollow.Logical formLearned from8 sentences. Trees can be hollow.Logical formLearned from8 sentences. Denials may ring hollow.Logical formLearned from8 sentences. A type can be hollow.Logical formLearned from8 sentences. A zoo can be hollow.Logical formLearned from8 sentences. Excuses may ring hollow.Logical formLearned from8 sentences. Notes can be hollow.Logical formLearned from8 sentences. Loaves may sound hollow.Logical formLearned from8 sentences. A building can be hollow.Logical formLearned from8 sentences. Insides can be hollow.Logical formLearned from8 sentences. A thought can be hollow.Logical formLearned from8 sentences.