Определите функцию «it», предложения переведите

1) How do they do it year after year growing more profitable? 2) It’s a question of finding the right market for a product. People have to expect it, and even demand it. 3) It is a sad story because it involves an outflow rather than inflow of capital into the country. 4) It is much wiser to allow cash to circulate, either to invest it or to have it in the bank, where it makes interest. 5) It was IBM who set the standard for the PC which others later imitated. 6) It is no secret that the gasoline crisis was due to a sharp reduction in the supplies of crude oil to the refinery. 7) According to marketing theory you first ascertain want or need and then create a product to satisfy it. 8) If you have a bank branch near your home, you may find it convenient to go there to draw your money out. 9) When it was time to repay, bank sent its clients a notification.10) It was planned to reduce maintenance costs. 11) This contract is not valid until it is signed by both parties. 12) It was Saturday October 6, 1979 – the key day in the history of the Federal Reserve System. It was on that day that the decision was made to cardinally change its functions.