An undertone can be hollow.Logical formLearned from3 sentences. A (plastic molding) can be hollow.Logical formLearned from3 sentences. Fiberglas can be hollow.Logical formLearned from3 sentences. A rotor can be hollow.Logical formLearned from3 sentences. Reasons may ring hollow.Logical formLearned from3 sentences. A foundation can be hollow.Logical formLearned from3 sentences. A spectacle can be hollow.Logical formLearned from3 sentences. An idea can be hollow.Logical formLearned from3 sentences. A (steel frame) can be hollow.Logical formLearned from3 sentences. Bats can be hollow.Logical formLearned from3 sentences. A vote can be hollow.Logical formLearned from3 sentences. Gold can be hollow.Logical formLearned from3 sentences. (Steel boxes) can be hollow.Logical formLearned from3 sentences. A pellet can be hollow.Logical formLearned from3 sentences. A (19th-century armory) may stand hollow.Logical formLearned from3 sentences.