A．两个极板间的电压
B．一个极板带的电荷量
C．两个极板间的距离
D．两个极板的正对面积
CD
阐明水产动物疾病发生的因素？
As an operating system repeatedly allocates and frees storage space, many physically separated unused areas appear. This phenomenon is called __( )__.
A．fragmentation
B．compaction
C．swapping
D．paging
