The earned value technique is a commonly used method of performance measurement. It integrates project scope, schedule, and cost measures to help the project management team assess project performance. If a project’s Cost Performance Index (CPI=EV/AC) value less than 1.0, it means that ______.

A．the cost savings for work completed

B．the project is ahead of its planned schedule

C．the cost overrun for work completed

D．less work was completed than was planned

泵用填料密封中，控制好填料与轴、填料与填料函接触面之间的间隙，以及就可以阻止介质泄漏的产生。