四、新情境 知识科普 阅读短文,选择正确的答案并回答问题。
When the traffic lights turn red, we must stop and wait. Why do we use the red lights to mean "stop"? Scattering (散射) happens when light goes into the air. It means that the air stops light from travelling far. Of all colours, red has the weakest (最弱的) scattering. So the red light passes the air easily and travels far. Using the red light can help drivers in far areas see the traffic lights. It helps drivers slow down or stop in time. If drivers see the light only when they are near the traffic lights, they may not stop the car in time. An accident may happen. Red can also excite people. We can act more quickly when we see the colour red. In a word, the red light helps drivers stop in time and helps prevent (防止) accidents.
()1. If scattering is strong, light will travel .
A. near
B. far
C. high
()2. The red light makes drivers .
A. see the lights in far areas
B. be excited and act quickly
C. both A and B
()3. Which is the best title for the passage?
A. Why do traffic accidents happen
B. How does the red light travel
C. Why do we use red traffic lights
4. 新趋势 开放性设问 你还知道红色在其他场景下的运用吗? 请用英文列举一个例子。

四、1. A 解析 根据短文中“Scattering happens when light goes into the air. It means that the air stops light from travelling far.”可知，散射意味着空气阻止光的传播，因此散射越强，光传播得越近。故选A。
2. C 解析 根据短文中“Using the red light can help drivers in far areas see the traffic lights.”及“Red can also excite people. We can act more quickly when we see the colour red.”可知，红灯可以让驾驶员在远处就能看到交通信号灯，并让他们保持兴奋且及时反应。故选C。
3. C
4. People in China use red at Chinese New Year. It's the colour of good luck and happiness. /People use red signs to mean “Danger!”。（答案不唯一）