In order to gain a bigger share in the international market, many state-run companies are striving _______ their products more competitive.

A．to make

B．making

C．to have made

D．having made

管道系统试验范围内的管道安装工程，除( )未施工外，均应按设计图纸全部完成，安装质量符合有关规定。

A．与设备连接

B．仪表接头

C．涂漆、绝热

D．安全附件接头