Social work is guided by altruistic values, based on scientific knowledge, and uses scientific methods to help others. According to the above definitions, which of the following is social work? ['The Guangzhou Asian Games Organizing Committee recruited a lot of volunteers in the school and the streets, which provided manpower guarantee for the successful hosting of the Asian Games.', "Non-governmental organizations such as Friends of Nature have carried out various forms of publicity activities over the years, raising people's environmental awareness.", 'Recently, many stars have been invited to participate in a charity auction.', 'Xiao Zhang is a professional psychological counselor. Every semester, he will compulsorily teach classes to nearby primary and secondary school students, explaining how to prevent juvenile delinquency, etc.']