题目

For generations, students were taught to stretch before playing games. Then the practice fell out of favor. Studies seemed to show that such stretching temporarily reduces muscular power, weakens athletic performance and increases the risk of injury. So most fitness experts currently advise against stretches before exercise. But now a new research indicates that they might not be such a bad idea after all.This month, the journal, Applied Physiology, Nutrition and Metabolism (APNM), published a study by four distinguished exercise scientists who analyzed more than 200 studies of how stretching Have you forgotten________a ruler from Tom？Please remember________it to him tomorrow.A．borrowing；to returnB．borrowing；returningC．to borrow；to returnD．to borrow：returning