UM2000型无绝缘轨道电路补偿电容的补偿节距，对2300Hz和2600Hz的轨道区段为（）。
A.50m
B.60m
C.70m
D.80m
参考答案：D
It's on the festival occasions________ the family get together________ he misses his late father.
A．where; that
B．which; when
C．when; that
D．that; when
什么是中性点位移现象
