Question 39 : C. run down
"Run down" means to reduce or stop something, which fits the context of military operations.
Question 40: D. make over
"Make over" means to improve or change something for the better, which makes sense for improving a losing football team.
Question 41: B. Lighten up
"Lighten up" is a common phrase meaning to relax or take things less seriously.
Question 42: C. write back
"Write back" means to respond to a letter.
Question 43: A. worsen
"Aggravated" means to make a situation worse.
Question 44: D. harmful
"Detrimental" means causing harm or damage.
Question 45: B. be successful
"Make a go of" something means to try to succeed in doing it.
Question 46: C. terrified
"Terrified" means very scared.
Question 47: D. usage
"Usage" refers to the way something is used.
Question 48: B. imitations
"Imitations" refers to copies or reproductions of something authentic.
Question 49: C. sufficient
"Sufficient" is the opposite of "inadequate."
Question 50: : B. poor
"Well off" refers to being financially comfortable, so the opposite is "poor"