A (battalion square) can be hollow.Logical formLearned from1 sentences. A t-piece can be hollow.Logical formLearned from1 sentences. Pouches can be hollow.Logical formLearned from1 sentences. A boss can be hollow.Logical formLearned from1 sentences. A (brass float) can be hollow.Logical formLearned from1 sentences. A tree-trunk can be hollow.Logical formLearned from1 sentences. (Winter quarters) can be in hollow trees.Logical formLearned from1 sentences. A sucking-trunk can be hollow.Logical formLearned from1 sentences. A green can be hollow.Logical formLearned from1 sentences. Concretions can be hollow.Logical formLearned from1 sentences. Flower-stalks can be hollow.Logical formLearned from1 sentences. Swages can be hollow.Logical formLearned from1 sentences. A (metal block) can be hollow.Logical formLearned from1 sentences. An (iron cylinder) can be hollow.Logical formLearned from1 sentences. (Corner walls) can be hollow.Logical formLearned from1 sentences.