Study on optimization of capital structure of listed agribusinesses 并列题名:Study on optimization of capital structure of listed agribusinesses Study on optimization of tax structure in the China's tax reform Study on the optimization of internal governance structure in colleges and universities Study on the optimization of Macau's industrial structure under one country two systems Study on the optimization of Macau's industrial structure under one country two systems. 并列题名:Study on optimization of tax structure in the china's tax reform