水土流失是一个复杂的地貌过程，它受多种因素的影响。
当齿条不受外力作用时，上扳手体与下扳手体通过花键接合在一起；
外源性犬尿烯酸对黑质多巴胺能神经元损伤的保护性作用
1·Endogenic and exogenic gold deposits in metamorphic regions in Hunanare characterized by occurrence of high-percentage single natural gold.
湖南变质岩区的内生与外生金矿床均以高成色的单一自然金产出为特征。
2·According to geological performances, Chinese phosphate deposits may be grouped into endogenic, exogenic and metamorphic.
以地质作用为主要依据，将中国磷矿分为内生磷矿床、外生磷矿床和变质磷矿床三大类。
3·Starting from the present research situation, endogenic and exogenic gold ore deposits and gold regional metallogeny have been discussed.
从研究现状出发，对内生、外生、区域成矿加以探讨。