电气设备的接地部分的对地（）与接地电流之比，称为接地装置的接地电阻。
参考答案：电压
— The weather has been very hot and dry.
— Yes. If it had rained even a drop, things would be much better now! And my vegetables _______. [ ]
A. wouldn't die
B. didn't die
C. hadn't died
D. wouldn't have died
脊髓空洞症的最好发部位是（）。
A.延髓
B.高颈髓
C.腰髓
D.中、下胸髓
E.下颈、上胸髓
