助手们仔细观察细菌对这种刺激物会产生什么反应。 The assistants observed carefully how the bacteria would react to this stimulus.
恐惧症对某一特定事物或情况持续的、不正常的或不合情理的恐惧，以致于要避开这些引起恐惧的刺激物 A persistent, abnormal, or irrational fear of a specific thing or situation that compels one to avoid the feared stimulus.
