A pin can be hollow.Logical formLearned from6 sentences. An enough can be hollow.Logical formLearned from6 sentences. A tone can be hollow.Logical formLearned from6 sentences. A person may be felt hollow.Logical formLearned from6 sentences. Units can be hollow.Logical formLearned from6 sentences. A ring can be hollow.Logical formLearned from6 sentences. A celebration can be hollow.Logical formLearned from6 sentences. A tavern can be hollow.Logical formLearned from6 sentences. A (test tube) can be hollow.Logical formLearned from6 sentences. Souls can be hollow.Logical formLearned from6 sentences. (Hair shafts) can be hollow.Logical formLearned from6 sentences. Words may feel hollow.Logical formLearned from6 sentences. A hill can be hollow.Logical formLearned from6 sentences. A continent can be hollow.Logical formLearned from6 sentences. Fears can be hollow.Logical formLearned from6 sentences.