[名词解释] 寄生Parasitism

终宿主definitive host 中间宿主intermediate host 共栖commensalism 钢轨伤损标记中表示有一定范围的轻伤标记是（）。 ["A、∣←△→∣","B、↑△","C、↑△↑","D、→△←"] 允许速度υmax≤120㎞/h钢轨波浪型磨耗谷深超过（）判轻伤。 ["A、0.2mm","B、0.3mm","C、0.5mm","D、1mm"] 寄生Parasitism