在高土壤电阻率的地区，降低接地电阻宜采用哪些方法？
参考答案：
深埋法，外引接地法，换土法，采用降阻剂等
— Football by the British at the beginning of last century.
— That's probably why football is one of popular games in England. [ ]
A. was invented, the most
B. invented, more
C. was invented, more
D. invented, the most
在井下可随时打开牵引部机盖观察内部结构。
