ZPW-2000A/K轨道电路为了消除列车车载信号的接收“盲区”,在道岔绝缘节处采用()和在轨道电路收发端处采用轨道电路钢轨引接线迂回的方法。
参考答案:跳线换位
轿底防跳、防压螺丝安装调整正确,防压螺丝()载重时应有()间隙。
There _____ few sheep here, but it was quite different in the past. [ ]
A. is
B. are
C. was
D. were