Related Clues:

• One held for questioning
• Licensing prerequisite, often
• Try to prove
• Cricket match
• Bee follower?
• Means of determining proficiency
• Gnarls Barkley singer ___-Lo
• Sound check
• Word after beta or acid
• Litmus ___
• Lab act
• It's often taken in silence
• Indifferent grade
• Grade determiner, often
• Average mark