abbr.直接还原铁（Direct Reduced Iron）；数据简化翻译程序（Data Reduction Interpreter）；研究与情报管理局（Directorate of Research and Information）；膳食营养参考摄入量（Dietary Reference Intakes）
For instance, in the early 2000's when I was an Executive Vice President at Disney responsible for corporate R&D, the media business began to experience rapid transformations.
例如，在20世纪初期（那时我还是迪斯尼研发部的副主管），媒体商业开始快速转型。
2
dxdy Last time I told you if we have dx dy we could switch it to r dr d theta.
上一次课提到，如果给出,我们可以把它转换为rdrdθ
3
R&D, i. e. Research & Development, is a whole process that includes basic theory research, technology research, products development and marketing development.