If you commission in to the Air Force as a non-rated officer (not a pilot, navigator, air battle manager) you'll be required to serve 4 years active duty. Pilots are required to serve 10 years. Basically it would be 8 years active (2ish years for flight school, 6 years actually flying) then 2 years inactive........
Stumbling block. For other uses, see Stumbling block (disambiguation). A stumbling block or scandal in the Bible is a metaphor for a behavior or attitude that leads another to sin.
Or it is chased by a shadow of bias, if supported by industry. Also, some sleep technology, such as memory foam, is relatively new, so it hasn't been well studied. But perhaps one of the more difficult stumbling blocks to testing the health benefits of mattresses such as memory foam is the subjective nature of sleep. It is simply difficult to measure.