A surface can be hollow.Logical formLearned from12 sentences. A party can be hollow.Logical formLearned from12 sentences. A legacy can be hollow.Logical formLearned from12 sentences. Invocations of development may ring hollow.Logical formLearned from12 sentences. A channel can be hollow.Logical formLearned from11 sentences. Pits can be hollow.Logical formLearned from11 sentences. Nanotubes can be hollow.Logical formLearned from11 sentences. A line can be hollow.Logical formLearned from11 sentences. A dome can be hollow.Logical formLearned from11 sentences. A conductor can be hollow.Logical formLearned from11 sentences. Crests can be hollow.Logical formLearned from11 sentences. A socket can be hollow.Logical formLearned from11 sentences. Stumps can be hollow.Logical formLearned from11 sentences. A concept can be hollow.Logical formLearned from11 sentences. Figurines can be hollow.Logical formLearned from11 sentences.