The direction of the current is reversed . 电流方向倒换。
The boy moved restlessly from one foot to the other, keeping his eyes down, and for the most part only half singing . 那个男孩心神不定地倒换着两只脚,眼睛总是望着地,多半只是半心半意地唱。
Replace one of the cooling water pumps for the brake 倒换一台刹车冷却水泵。
Test methods of protection schemes for sdh rings Sdh环网保护倒换测试方法
A new protection mechanism in rpr 弹性分组环中一种新型保护倒换机制