A:外耳道
B:听小骨
C:听觉神经
D:咽鼓管
如图,△ABC中,∠ACB=90°,CD⊥AB于D,BD=2,AD=8,求S△ABC.
Trees and flowers ________every year to make our country more beautiful.
如图,AB和CD都是⊙O的直径,∠AOC=56°,则∠C的度数是( )