You are trying to determine what cost and schedule trade-off will be most appropriate for your project. You have the option to select either a more experienced person at $120 per hour who can do the task in 45 days or a less experienced person at $80 per hour who can do the same task in 65 days. A tool you can use to facilitate making the decision is ______ .

A．cost of quality

B．cause-and-effect diagram

C．design of experiments

D．network diagrams

在带传动中，当传递的功率一定时，若带速降低，则传递的圆周力就( )，就容易发生打滑。

A．减小

B．明显地减小

C．增大