impenetrable

adj. 不能穿过的,不可理喻的,费解的,顽固的

impassivity, impatience, impatient, impatiently, impeach, impeachable, impeachment, impeccable, impeccably, impecunious, impecuniously, impecuniousness, impedance, impede, impediment, impedimenta, impel, impend, impending, impenetrability, impenetrably, impenitence, impenitent, impenitently, imperative, imperatively, imperceptible, imperceptibly, imperfect, imperfection, imperfectly, imperial, imperialism, imperialist, imperialistic, imperially, imperil, imperious, imperiously, imperiousness,