A flap can be hollow.Logical formLearned from2 sentences. Works can be hollow.Logical formLearned from2 sentences. (Force years) can be hollow.Logical formLearned from2 sentences. Facts may ring hollow.Logical formLearned from2 sentences. An image can be hollow.Logical formLearned from2 sentences. A (stone monument) can be hollow.Logical formLearned from2 sentences. An endorsement can be hollow.Logical formLearned from2 sentences. Comparisons can be hollow.Logical formLearned from2 sentences. A misery can be hollow.Logical formLearned from2 sentences. Segments can be hollow.Logical formLearned from2 sentences. A church can be hollow.Logical formLearned from2 sentences. A ritual can be hollow.Logical formLearned from2 sentences. Cylinders can be hollow.Logical formLearned from2 sentences. Claims of a country may ring hollow.Logical formLearned from2 sentences. Matrices can be hollow.Logical formLearned from2 sentences.