Hello, I just found out that I will be facing a pre-employment polygraph test very soon. In order to prepare myself I plan on giving myself practice tests by recording (audibly) questions on my phone and having them played while I sit in a chair and answer them.
My questions are:
What would be some good questions for me to practice with?

How much time should be in between each question? (I thought I had read in the book that the examiner asks questions 20-30 seconds apart)

How many questions should I include in my practice test (I have no clue how many questions the examiner will ask me during the test.)
Thank you!