It is not hard to imagine that behind the eye-opening progress Japanese language education has made are the extraordinary efforts of Japanese language educators and researchers.
It isn't hard to imagine how difficult it has become for foreign students to find (examples of) traditional Japanese culture.
(d).
好きな文芸の道と経営者としての責任の間で、多才な彼が苦悩していたことは想像にかたくない。
It isn't hard to imagine that a man of his versatile talents struggled (to choose) between his beloved world of literature and his managerial responsibilities.
(e).
その青年が非常に心優しく生真面目かつ勉学熱心な人間だったことは推測にかたくない。
It is easy to imagine that young man as a gentle, serious and diligent person.
It isn't hard to predict that if people who live overseas and actively criticize the military regime of their country go home, most likely they will be put into prison and tortured.