新更换的轮对，轮距应小于轨距（）mm。
A、6
B、7
C、8
D、9
参考答案：A
People take naps at noon in warmer climates, ____the heat makes work difficult in the
early afternoon. [ ]
A. which
B. what
C. where
D. when
ZPW-2000A型轨道电路电缆芯线全程对地绝缘大于（）。
A、1MΩ
B、2MΩ
C、3MΩ
D、4MΩ
