行驶的车辆突然刹车时如图所示，人向前倾的原因是(   )

It's black and white．It has a short tail．It's a      ．    

改变外界条件可以影响化学反应速率，针对H₂（g）+I₂（g）⇌2HI（g），其中能使活化分子百分数增加的是（   ）

①增加反应物浓度   ②增大气体的压强   ③升高体系的温度   ④使用催化剂

    What is color? Why do some of the things around us look red, some green, others blue?
    Colors are really made by deflected (反射) light. We see color because most of the things reflect light. In the same way, if something is green, it reflects most of the green light. If something reflects all light, it is white. If it doesn't reflect any light, it is black.
    Some of the light is reflected and some is taken in (吸引) and turned into (变成) heat (热能).The darker the color is, the less light is reflected, the more light is taken in. So dark-colored clothes are warmer in the sun than light-colored clothes.