信号刺激，激励信号
stimulus───n.刺激；激励；刺激物
signal───adj.显著的；作为信号的；n.(Signal)人名；(瑞典)西格纳尔；vt.标志；用信号通知；表示；n.信号；暗号；导火线；vi.发信号
discriminative stimulus───辨别刺激；识别的刺激
signal wire───[通信]信号线
radio signal───无线电讯号；无线电信号
home signal───进站信号（机）；[铁路]进站信号；[铁路]进站信号机
signal processing───[通信]信号处理
alarm signal───[安全]警报信号；n.警报，警报信号
digital signal───[自][通信]数字信号
The researchers also tested the flies' saliva for enzymes that signal sleepiness and measured the flies' ability to associate a light with an unpleasant stimulus.───研究人员还检测了果蝇唾液中显示困倦程度的酶，还测试了果蝇将光亮与令人不快的刺激联系起来的能力。
Living activities of cell require the stimulation of information objects. If one once loses the signal stimulus, cells lack the activities.───细胞生命活动需要信息物质的刺激，一旦失去信号刺激，细胞就缺乏生活力。
It predicts that the best timing is when the conditioned stimulus, which is the signal, comes before the unconditioned stimulus, which is what you have to prepare for.───它预测，最佳的时机，莫过于作为信号的条件刺激，出现在需要你做准备的，非条件刺激之前。