Teacher:Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.
Teacher: Now, understand the problem? Solve this instance: Question: Is regular Chinese Green Tea Consumption Protective for Diabetic Retinopathy : A Clinic-Based Case-Control Study?
Answer: Diabetic patients who had regularly drunk Chinese green tea every week for at least one year in their lives had a DR risk reduction of about 50% compared with those who had not. Regular Chinese green tea consumption may be a novel approach for the prevention of DR.
Student:
yes