题目

In 1988, a company in Ohio invented an alcohol-based hand cleaner, which was meant to be used by health-care worker; when soap and water were unavailable. Joe Kanfer, the company's C. E. O., told me recently, “there were a couple of other alcohol products out there, but they were really ugly. Either they were greasy (油腻的) or they burned your hands white.” Kanfer took a year and a half to develop this product which is visually appealing and does almost no harm to one's skin. Still. Kanfer lost money on it for more than a decade because people couldn't get what it was for.   �阅读下列材料：20世纪70年代，我市粮食亩产量一般年份在75—125千克之间。1982年以来，改革的春风吹遍了农村大地，我市农业有了很大发展，仅粮食一项，2004年全市单产417千克/亩，总产量达185万吨，实现了历史性突破。我市的粮食生产发生的变化主要得益于我国哪项农村政策的实施？