thE mAin purposE oF this tExt is to ________.
A．tEll stuDEnts oF importAnt sChEDulE ChAngEs
B．tEll stuDEnts oF nEw Bus AnD liBrAry sErviCEs
C．show thE ExCEllEnt sErviCEs For stuDEnts
D．Ask stuDEnts to rEnEw thEir liBrAry CArDs