Old-fashioned phones matter when wireless networks _____ in disasters.

He tried to join the army but was _____ because of poor health, which made him depressed. 

 After that, he knew he could ________ any emergency by doing what he could to the best of his ability.

If a student ____ in the exam, he won’t escape punishment.

 Though you've got a tight schedule these days, I should be ________ if you could spare time to attend our meeting today.