SimilarityRank
the_big_challenge 0.842 19695
great_challenge 0.789 59535
the_major_challenge 0.769 66525
big_challenge 0.755 46944
major_challenge 0.689 94021
many_challenge 0.686 34197
the_main_challenge 0.684 52376
the_key_challenge 0.670 74955
the_most_challenging 0.614 54484
challenge 0.612 222
another_challenge 0.612 48760
the_big_problem 0.601 25566
that_we_face 0.589 59337
we_face 0.587 17796
the_hard_thing 0.579 86990
face_many_challenge 0.572 78198
the_most_difficult 0.569 35489
environmental_challenge 0.553 68452
the_most_important_issue 0.552 75837
face_today 0.549 76202
challenge_face 0.548 32972
current_challenge 0.545 50315
be_the_most_difficult 0.542 91080
challenge_we_face 0.540 47011
more_challenging 0.540 31394