电容器串联时，其总容量是（）的．
A、增大
B、减小
C、不变
D、无限递增
参考答案：B
下列物理量在运算过程中遵循平行四边形定则的有
A．路程
B．速度
C．力
D．质量
All experts agree that the most important consideration with diet drugs is carefully ___ the risks and benefits .
A．weighing
B．checking
C．taking
D．supposing
