Since a participle takes the form: verb + -ing, the only word in this sentence which has such a form is B, 'challenging'. 'Puzzle' is a noun, 'crossword' is an adjective, 'created' is a verb.
The answer is Historical works that are so important they change the way we see the world.
Explanation:
Seminal works, sometimes called pivotal or landmark studies, are articles that initially presented an idea of great importance or influence within a particular discipline.
Answer: 12
Explanation: Preciate dez pts bro! Thx