Related Clues:

• Licensing prerequisite, often
• Try to prove
• Cricket match
• Pump, in a way
• Means of determining proficiency
• Sound check
• Word after beta or acid
• Popped item?
• Litmus ___
• Lab act
• It's often taken in silence
• ''Pop'' test
• Grade determiner, often
• Mike holder's opening, often
• It may be unwelcome when popped