attackn.攻击；抨击v.攻击；抨击；发动攻击；（疾病）侵袭attacking act攻击行为attack points攻击点attacking leg进攻腿attack region攻击区attacked with遭到 ... 攻击； 害attack a fire扑火attack method攻击方法attacking aim攻击目标attack factor相关因素attack course载机攻击航线

1. What is the usual age of the onset of keratoconus?
   圆锥角膜通常的发病年龄？