感应电流的效果总是____ .The effect of the inductive current is always___.
A.
总是反抗引起感应电流的原因; always resist the cause of induced current;
B.
总是增强引起感应电流的原因; always enhance the cause of induced current;
C.
有时反抗有时增强引起感应电流的原因; sometimes resist and sometimes enhance the cause of induced current;
D.
或者反抗或者增强引起感应电流的原因; either resist or enhance the cause of induced current;