An archtop can be hollow.Logical formLearned from3 sentences. Stakes can be hollow.Logical formLearned from3 sentences. A pass can be hollow.Logical formLearned from3 sentences. A (propeller hub) can be hollow.Logical formLearned from3 sentences. A nest can be hollow.Logical formLearned from3 sentences. An effort may ring hollow.Logical formLearned from3 sentences. (Post mills) can be hollow.Logical formLearned from3 sentences. A wilderness can be hollow.Logical formLearned from3 sentences. A portion can be hollow.Logical formLearned from3 sentences. A track can be hollow.Logical formLearned from3 sentences. (Bamboo stalks) can be hollow.Logical formLearned from3 sentences. A flashlamp can be hollow.Logical formLearned from3 sentences. Legions can be hollow.Logical formLearned from3 sentences. A (box girder) can be hollow.Logical formLearned from3 sentences. Hollow bastion may undergo ruins.Logical formLearned from3 sentences.