I would say that the answer should be "Helen's challenges with the frustration of learning to communicate".as a blind-deaf person and the excellent analogy with being shrouded in fog and not having how to determine where she was headed but love giving her the light to find her way and eventually get a degree at university.
The word that could fit the gap is definitely a possessive pronoun such as their, used because it refers to the previous pronoun them
Answer:
In 2003, Patterson was appointed chief justice of a "Special Supreme Court" that tried the case of Alabama Chief Justice Roy Moore, who appealed his removal from office after he had refused to remove a monument of the Ten Commandments from the courthouse despite orders from a federal court judge to do so.
Hope I helped!
Answer:
I think it's compound. Not sure.
