导致不同管理阶层之间冲突的最通常原因是()
参考答案：项目目标不清楚
What's wrong with your car?
- Well, as you know, cars usually_______ start in winter.
A．don't
B．shan't
C．can't
D．won't
A．变压器输出端所接电压表的示数为20V
B．变压器的输出功率为200W
C．变压器输出端的交流电的频率为50Hz
D．穿过变压器铁芯的磁通量变化率的最大值为20/n2Wb/s
V
/n2Wb/s