A：My
B：I'm
C：my
清朝有位官员叫叶存仁，有一次一位手下趁夜色给他送礼，他严词相拒，并写下了“不畏人知畏天知”的千古警句，这表明（ ）
——What do you often do_______ classes to relax yourselves?——We often do eye exercises, listen to music or do some running around the school.
圆锥的高h、母线长l满足l=2h，底面半径为r，则其侧面展开图形的面积为（ ）
