信号设备当合用接地体时，接地电阻越小越好，规定不大于（）欧姆。
A、1
B、2
C、3
D、4
参考答案：A
289. Our victory in the school sports meet resulted from the collective__________of all the classmates.
A．wisdom
B．wisdoms
C．brightness
D．cleverness
The reason__________ the president of Czech is widely discussed recently is__________ he was seen
"to steal" a pen at a press conference in Chile. [ ]
A. why; because
B. that; that
C. why; that
D. why; why
