How to use the words dedicated and obstacle in a sentence

The boy was dedicated to train until he could finally pass the obstacle.

- "the answers are a and b.  

when cullen speaks of planting while others reap, and standing "abject and mute," he is speaking about the racial injustices present in american society. as these injustices have changed over time, the american identity  has also shifted. those changes are, in turn, reflected in american literature."

i think the answer might compound