Sometimes a sudden shift in color can be used to startle potential predators or threaten intruders.
有时候，色彩的快速变换可以用来惊吓掠食者或威胁入侵者。
2
The researchers found that people given propranolol had a much lower emotional response—measured by a startle reflex—to the images.
研究者发现，服用了心得安的人们对这些图片的情绪反应——通过惊吓反射测量——低了很多。
3
Military researchers are looking to combine an acoustic gunshot detector with a dazzling laser that will startle shooters who take aim at American helos.