Research on the agricultural products trade between China and USA 并列题名：Research on the agricultural products trade between China and USA Research on the agricultural productive service industry 并列题名：Research on the agricultural productive service industry Comparison of agricultural total factor productivity between China and Japan Research on trade competitiveness of agricultural products between China and Latin America Research on edible agricultural products' safety 并列题名：Comparison of agricultural total factor productivity between China and Japan 并列题名：Research on trade competitiveness of agricultural products between China and Latin America Research on security system of agricultural products quality and safety in China