Research on optimization of distribution for regional cold chain logistics of agricultural products Selection and optimization of distribution channels for agricultural products Research on the construction of regional public brands for agricultural products Research on the the route of regional public brand construction of agricultural products 并列题名：Selection and optimization of distribution channels for agricultural products Research on conflict and integration of marketing channel of agriculutural products Research on soil pollution prevention and control of agricultural products 并列题名：Research on the the route of regional public brand construction of agricultural products 并列题名：Research on conflict and integration of marketing channel of agriculutural products