Blocks can be hollow.Logical formLearned from11 sentences. (Steel bars) can be hollow.Logical formLearned from11 sentences. Atoms can be hollow.Logical formLearned from11 sentences. Nozzles can be hollow.Logical formLearned from11 sentences. A feel can be hollow.Logical formLearned from11 sentences. An axis can be hollow.Logical formLearned from11 sentences. A park can be hollow.Logical formLearned from11 sentences. Calls may ring hollow.Logical formLearned from11 sentences. Threats may prove hollow.Logical formLearned from11 sentences. A receptacle can be hollow.Logical formLearned from10 sentences. A (log ride) can be hollow.Logical formLearned from10 sentences. A mill can be hollow.Logical formLearned from10 sentences. Camshafts can be hollow.Logical formLearned from10 sentences. A bridge can be hollow.Logical formLearned from10 sentences. A (steel tube) can be hollow.Logical formLearned from10 sentences.