完形填空。 People are often killed when they __ 1 ___ the road. Most of these people are old people and children. Old people are often killed because they can not see __ 2 ___ hear very well. Children are often killed because they are not __ 3 ___. They forget to look and listen before they cross the road. A car, truck or bus cannot stop very ___4__ . If the car-is going very fast, it will travel __5___ meters  before it stops. People don't always understand this. They think a car can stop __ 6 ___ a few meters. The  faster a car __ 7 ___, the longer it takes to ___ 8 __. It is very difficult for a person to know how fast a car is traveling. The ___ 9 __safe way to cross the road is to look in both directions, right and left. Then ___ 10 __ the road is clear, it is safe to cross. The right way to cross the road ___ 11 __to walk quickly. It is not __ 12 ___ to run across the road. If people run across the road, they may fall __ 13 ___. (     ) 1．A．over (     ) 2．A．and (     ) 3．A．care (     ) 4．A．shortly (     ) 5．A．much (     ) 6．A．during (     ) 7．A．traveling (     ) 8．A．fly (     ) 9．A．few (     ) 10．A．if (     ) 11．A．is (     ) 12．A．hard (     ) 13．A．down B．across B．but B．careful B．early B．more B．among B．is traveling B．go B．only B．before B．has B．danger B．to C．cross C．both C．strong C．quickly C．many C．between C．travel C．stop C．often C．which C．are C．safe C．up D．through D．or D．healthy D．slowly D．a lot D．in D．is to travel D．move D．always D．what D．have D．dangerous D．under