Behavioral economics believes that reciprocal behavior is a conditional cooperative behavior that rewards behaviors of goodwill and helping others. Reciprocal behavior benefits the other party by implementing a form of reward, which is often achieved by reducing or harming self-interest. According to the above definition, Which of the following are reciprocal behaviors:. ['Entrepreneur Liu Zhigang donates to cancer patients every year and wins praise from all walks of life.', 'Thanks to my colleagues for saving the child who fell into the water, Li Ling gave up her chance of promotion and raise.', 'Xiao Wang used his spare time to help new college students get familiar with the business, so he was also trained.', 'For long-term joint cooperation, the general manager provides many favorable conditions for suppliers.']