n.密集，收缩...

arctation的音标：arctation的英式发音音标为：[ɑ:k'teɪʃn]arctation的美式发音音标为：[ɑk'teɪʃn]...

孔道狭窄...

The characteristics of small faults are coarctation and zonation with clear direction.小断层具有密集成带的特点,且方向性明显,成为影响煤矿生产的主要地质因素.This portion of aorta was resected from a patient with a coarctation.主动脉的一部分,通过切除一例主动脉狭窄病人的主动脉而得来....

coarctation的音标：coarctation的英式发音音标为：[ˌkəʊɑ:k'teɪʃən]coarctation的美式发音音标为：[ˌkoʊɑk'teɪʃən]...