1·The horse spooked at the siren.
警报器一响，马受惊了。
—— 《牛津词典》
2·(An everyday example of this effect is the change of pitch of an ambulance siren as it approaches and recedes.) It was thus possible to measure the force applied to the ions.
根据多普勒效应，光被离子反射后，靠近激光器的光的频率会高于远离激光器的光的频率，（日常生活中，救护车警报器的音调随着车的远近也变化，就是这个道理）这才有可能测量先前对离子施加的力的大小。
3·A similar effect, called the Doppler shift, causes the siren of an approaching ambulance to apparently change pitch as it passes you.
它是一种类似的多普勒频移的效应，就像救护车在你面前驶过时，会促使逐渐靠近你的警报器明显地改变其音调那样。
4·With siren howling in the night, the ambulance rushes the infant to the neonatal intensive care unit at St. Mary's Hospital in Knoxville, Tennessee.
伴着晚上警报器的鸣叫声，救护车把婴儿送到田纳西州诺克斯维尔市的圣玛丽医院，新生儿重病特护区。
1·It is helpful to use well-known ideas such as an ambulance siren or a gunshot because these sounds carry a lot of context with them.
使用诸如救护车汽笛或枪身之类众所周知的音效是有帮助的，因为这些声音本身蕴含了环境信息。
2·It is helpful to use well-known ideas such as an ambulance siren or a gunshot, because these sounds carry a lot of context with them.
使用诸如救护车汽笛或礼炮之类著名的音效是有帮助的，因为这些声音本身蕴含了环境信息。
3·The wails of the siren woke the people out of their dreams.
汽笛的啸鸣把人们从睡梦中惊醒。
4·No noise of the city siren, no piles of reference books that we learn.
没城市汽笛地喧哗，没成堆地参考书自己们进修。
1·Think of the pitch of a siren on an ambulance, which goes from high to low as it passes the observer.
试想救护车上的报警器，经过观测者的时候，其音调会呈现出由高到低的变化。
2·A military helicopter hovered overhead, its emergency siren howling over the roar of its blades.
一架军用直升机在头顶盘旋，轰鸣的螺旋桨上方，紧急报警器发出悲号。
1·The words “Starbucks Coffee” around the outer rung of the circular design was dropped, leaving only the crowned siren with flowing hair.
环绕圆形外环设计的“Starbucks Coffee”（星巴克咖啡）这几个字被去掉，只留下加冕的海妖和她的飘逸长发