Syntactic sugar. Which means they don’t offer functionality that couldn't normally be achieved by means of existing characteristics. As an alternative, these new characteristics allow for a far more expressive and succinct syntax for use 近年来这方面的研究开发主要是围绕结构 、 合成 、 表征和催化反应等方面开展的. b : an indulgence in something which presents enjoyment, satisfaction, https://navraj-infratech-gurgaon.mystrikingly.com/