在街上行走,有时会看到一辆救护车,或者消防车或者警车呼啸着飞驰而过。而这些车子都有个共同点,那就是车顶上都有一个闪烁的警报器,而且警报器都是红色的。甚至,连消防车的车身都是红色的。同学们,你们知道为什么吗+为了这个问题,我可查了不少资料呢。如果你也想知道问题的答 Walking in the street, sometimes seeing an ambulance, or fire engines or police cars whistling past. And all of these cars have one thing in common: a blinking siren on the roof and red sirens. Even the body of the fire truck is red. Students, do you know why? I checked a lot of information for this problem. If you also want to know the answer to the question