Practice question What FLHSMV fee applies to a CDL knowledge retest? Skip the check if the tractor feels normal$$10 knowledge retest feeSpeed up and make a sharp correctionUse the trailer hand valve as the main control Answer: B — $$10 knowledge retest fee The correct answer is shown above. Try the full quiz for additional practice. Practice more: FL CDL Combination Practice Questions - Florida CDL Combination Vehicles Test Exam →