Exacto爱山吐牌手表exactadj.精密严谨的；确切的exact calculation精确计算exact probability确切概率exacting bacteria需氨基酸细菌exacting practice大强度训练exact to the life和实物丝毫不差的exact acquisition精确探测exact propability确切概率法, 直接概率法exact orientation准确定位exact information可靠情报exact upper bound上确界

1. It was difficult to tell his exact age.
   很难判断他到底多大岁数。