Related Clues:

• Checked
• Known to be in working order
• Lab work
• See 19-Down
• See 56-Across
• Midterm, for one
• Use a cupel
• Dreaded class word
• Step in getting a license
• Final, perhaps
• Pro or con follower
• It makes the grade
• Tried and true
• Word with litmus or taste
• Try out