An entrance can be hollow.Logical formLearned from2 sentences. Threats may ring hollow.Logical formLearned from2 sentences. An (iron casting) can be hollow.Logical formLearned from2 sentences. Monuments of power can be hollow.Logical formLearned from2 sentences. A bell can be hollow.Logical formLearned from2 sentences. An armor can be hollow.Logical formLearned from2 sentences. A value can be hollow.Logical formLearned from2 sentences. A genre can be hollow.Logical formLearned from2 sentences. An opportunity can be hollow.Logical formLearned from2 sentences. A pineapple can be hollow.Logical formLearned from2 sentences. A van can be hollow.Logical formLearned from2 sentences. A hold can be hollow.Logical formLearned from2 sentences. A birdcage can be hollow.Logical formLearned from2 sentences. A door can be hollow.Logical formLearned from2 sentences. A pot can be hollow.Logical formLearned from2 sentences.