Can you be more specific with your question I don’t think we understand
The sentence includes two words with virtually identical meanings: duplicity and dishonesty. Therefore, the context clue that's found in the sentence is synonym, as the two are synonymous.
Vain is the correct answer. Plug in each word given into the sentence and then read it to see if the sentence makes sense.
"We may try in credibility to solve our problems on our own.." Credibility is incorrect.
"We may try in predict to solve our problems on our own.." Predict is incorrect.
"We may try in forgive to solve our problems on our own.." Forgive is incorrect.
"We may try in vain to solve our problems on our own.." Vain is correct!
Hope this helps! (:
