短語詞組短語cancer parasitism 癌寄生性occasional parasitism 偶然寄生epi parasitism 重寄生concurrent parasitism 兼性寄生obligatory parasitism 專性寄生parasitism rate 寄生率direct parasitism 菌寄生parasitism effect 寄生傚應tertiary parasitism 三次寄生 返回 parasitism