impregnatev.注入;使充满;使饱和;使怀孕adj.充满的;怀孕的
impreciseadj.不精确的
impregnable virtue坚贞不屈的情操
impregnable defenses攻不破的防御工事
"an impregnable fortress"
"fortifications that made the frontier inviolable"
"a secure telephone connection"
"an impregnable argument"
"impregnable self-confidence"