Principles and policies of agriculture, rural areas and farmers. "Three Supports and One Support" is a policy implemented by graduates at the grassroots level, which means that after graduation, college students go to the rural grassroots level to engage in supporting agriculture, teaching, helping doctors and helping the poor. The principles and policies of agriculture, rural areas and farmers' pre-job training, as well as the current situation of grass-roots work in this area, the basic situation of the proposed service units and posts, etc. , but also introduce the life, people's feelings and customs of the service places to help them adapt to the working and living environment more quickly.