"he enjoys their praising her children at school. using passive voice, 为什么要加being？"

In this sentence, the phrase "their praising her children at school" is in active voice. To convert it into passive voice, the sentence should be rephrased as: "She enjoys her children being praised at school." In the passive voice construction, the subject (her children) becomes the object (her children) and the verb (praising) is changed to its passive form (being praised). The use of "being" is necessary to indicate the action happening to the subject (her children).

途牛指出，今年三季度，途牛用户暑期及中秋国庆假期出游需求释放显著，旅游消费迎来爆发式增长。， 就是理解不了江大乔的性子，他就不适合当队长，有什么事，都藏在心底不说，马嘉所谓的犯了下了很多错，有多些是和江大乔缺乏沟通能力有关的，马嘉是不安分子，他江大乔同样也是如此啊。

现场调研了企业仓库管理、进出库管理、信息系统化管理等方面情况，同时技术专家讲解了DCMM标准及评估要求。，英国研究人员开发了一种可完全控制的全封闭水产养殖系统，能将船虫培育成营养丰富的海鲜，并将其命名为裸蛤。

比赛中，参赛实习生各展所长，尽展风采。，在2013年财报中，公司在介绍十周年的成果时也称：“我们以人为本，着力打造了一支过硬的队伍”。