What skills and knowledge does a good manager need?why？

First of all, he or she needs management skills;

Second, he or she needs a knowledge of art of leadership;

Third, he needs skills of training;

Fourth, he or she needs to know his or her subordinates' needs and wants;

Fifth, he or she needs to know the products quite well;

sixly, he or she should know how to make plans and budgets.

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一个好的管理者需要怎样的技术和知识？为什么？

什么技能和知识也需要一个良好的经理为什么？