电源设备容量的选择,主要的依据是在一定工作条件下,向负载提供的()。
A.电压量
B.功率量
C.电流量
参考答案:C
The whole book ________ 12 units, _________ two mainly revisions.
A.contains; containing
B.includes; contain
C.contains; including
D.includes; including
情志因素是如何影响体质的?