py.re.thrinn.(名词)Either of two viscous liquid esters, C2H 28O 3 or C 22H 28O 5, that are extracted from pyrethrum flowers and used as insecticides. 除虫菊酯:两种液体粘性酯中的任一种,C2H 28O 3或C 22H 28O 5,从红花除虫菊花上提取,用于杀死昆虫 来源:pyrethr(um) pyrethr(um)-in -in