Vocabulary

radicalized - to make radical or more radical especially in politics.
"radicalized many hip students who had once believed in the power of example."
To be radical for something means to do something in an extreme way. Not in an ordinary way.
A clue I found when I read this word was hip. To be a hip person could mean to be an extreme person. Someone that stands out.
detrimental - harmful; injurious; prejudicial
"this may have a detrimental effect on learning the effectiveness of treatments for these children.
When I think of the word detrimental I think of something bad. Like an injury.
My clue was when it said that it may effect the learning of the children. 
entrench - to dig trenches for defensive purposes around (oneself, a military position, etc.)
"All he could do was dig. He used his entrenching tool like an ax..."
When I think of the word "entrench" I think of military people digging holes for cover.
When the author said all he could do was dig, that was my clue that entrench means to dig holes.