Social welfare: refers to the improvement of people's living conditions and the quality of life through social mutual assistance. Which of the following are social benefits? ['A sick person is very expensive to be hospitalized, a good friend sends 500 yuan in cash.', 'Someone has been laid off for two years and started receiving unemployment insurance benefits.', 'c. A government agency issues valuable shopping vouchers to its staff.', "Someone participates in a company's raffle and gets a chance to travel to Hainan."]