benzole forerunning苯初馏
forerunning phenomena火山喷发前兆;前兆现象
Benzol forerunning苯头分
light benzol forerunning轻苯初馏
forerunning effect of earthquake地震前兆
forerunning phenomena of volcanic eruptions火山喷火前兆
hollow-shaft forerunning girdle-less three-wing bore空心管式先导型无腰带三翼钻头
V（动词） to serve as a herald for 为先驱