Investment in product quality improvement, especially defect prevention and appraisal, can often be borne by ______ .

A) the organization
B) the project management team
C) executive management
D) the project

锅筒是锅炉受压元件中最重要的部件，它由______等零、组件组装焊接而成。

A．分离器

B．内部装置

C．封头

D．筒体

E．下降管

F．管接头