magistral

the magistral line of fortifications.

防御工事线

It even results in geologic hazard;for the mine geologic hazard,the background of physiognomy is the potential factor,while the irrational exploitation is the magistral factor.

矿山地质灾害生，地质地貌背景是潜在，不合理开采方法是，降雨和水文条件是激灾难生直接原。

Chapter four is the research on diversity architectures of agriculture technique extension mode, analyzing the necessity that diversified mode constuct. several magistral modes is comparative studied.

第四章,多元化农业技术推广模式构建。