褶曲枢纽
褶曲岩层的同一层面与轴面相交的连线。枢纽可呈水平、倾斜或起伏(倾伏)状,表示褶曲有倾向延伸的变化。
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
免费的网站请分享给朋友吧