A surfboard can be hollow.Logical formLearned from3 sentences. An age can be hollow.Logical formLearned from3 sentences. A cord can be hollow.Logical formLearned from3 sentences. A reverberation can be hollow.Logical formLearned from3 sentences. A parody can be hollow.Logical formLearned from3 sentences. (Wood doors) can be hollow.Logical formLearned from3 sentences. A cut can be hollow.Logical formLearned from3 sentences. A book can be hollow.Logical formLearned from3 sentences. A record can be hollow.Logical formLearned from3 sentences. Arguments may sound hollow.Logical formLearned from3 sentences. A (wind instrument) can be hollow.Logical formLearned from3 sentences. Sides can be hollow.Logical formLearned from3 sentences. Offers can be hollow.Logical formLearned from3 sentences. A honor can be hollow.Logical formLearned from3 sentences. A rivet can be hollow.Logical formLearned from3 sentences.