11. They did all of this in four hours. 12. And that process takes about two hours. 13. But nine of the 10 in those first hours. 14. And in two hours, after their backs were broke, 15. And it will refrigerate for 24 hours. 16. I'm like, “That's stupid because you have to work for five hours. 17. The effects start after about 20 minutes and can last several hours. 18. %H hours, %M minutes and %S seconds. 19. One dose of amphetamine can last three to four hours. 20. Use of solar heaters help save electricity in peak hours.
