An owl can be hollow.Logical formLearned from3 sentences. A disappointment can be hollow.Logical formLearned from3 sentences. Clangs can be hollow.Logical formLearned from3 sentences. A knock may sound hollow.Logical formLearned from3 sentences. A nothingness can be hollow.Logical formLearned from3 sentences. A bottom of a base can be hollow.Logical formLearned from3 sentences. A (body sound) can be hollow.Logical formLearned from3 sentences. A tornado can be hollow.Logical formLearned from3 sentences. A person may become a hollow man.Logical formLearned from3 sentences. Chants can be hollow.Logical formLearned from3 sentences. A protest can be hollow.Logical formLearned from3 sentences. A plot can be hollow.Logical formLearned from3 sentences. A charm can be hollow.Logical formLearned from3 sentences. Blue eyes can be hollow.Logical formLearned from3 sentences. An ambition can be hollow.Logical formLearned from3 sentences.