the relation between two different species of organisms that are interdependent; each gains benefits from the other
同义词：symbiosis
mutualism详细解释
mu.tu.al.ism n.（名词）An association between organisms of two different species in which each member benefits.互靠论：两种不同种类之间互利的联合 【引伸】 mu.tualis.tic adj.（形容词）
