internal rib内肋筋internaladj.国内的；内部的；身内的internal hydrocephalus梗阻性脑积水internal contradiction内部矛盾internalrate of return内部收益率internalforce analysis内力分析internal point of view内在观点internal system number系统内部编号internal grinding head内圆磨头internal growth theory内部发展理论internal heat exchange内部热交换internal length scales内尺度律