29. What does the term 'interpolation' refer to in the context of precisionrecall curves? A. The process of adjusting the threshold for document relevance B. Estimating precision values at standard recall levels not directly observed in the data C. The connection of all points in the curve with straight lines D. A smoothing technique applied to the recall values E. All of the above 30. When evaluating text classification algorithms, what does the term 'supervised' imply? A. The algorithm can learn and make predictions without any labeled training data. B. The algorithm requires a set of pre-labeled data to learn the classification model. C. The algorithm operates based on predefined rules without any learning phase. D. The algorithm solely relies on the structure of the input data without using any labels. E. All of the above