People are often killed while c____ the road. Most of them are old people and c____ . Old people are often killed because they are careless. People should look and listen b____ they cross the road. A car, a truck or a bus can't stop very q____ if it is going very fast. It will travel many meters before it s____ . Pedestrian(行人)don't know this. They think that a car can stop right away. It is h____ for a pedestrian to know how fast a car is traveling. The only s____ way to cross the road is to look at b____ ways, right and left. The correct way to cross the road is t____ walk quickly when the traffic l____ turn green.