A Killer bees started in Brazil in 1957. A scientist in Sao Paulo wanted bees to make more honey（蜂蜜）. So he put forty-six African bees with some Brazilian bees .The bees bred（繁殖）and made a new kind of bees .But the new bees were a mistake .They didn’t want to make more honey .They wanted to attack .Then ,by accident ,twenty—six African bees escaped and bred with the Brazilian bees outside. Scientists could not control（控制） the problem. The bees increased fast .They went from Brazil to Venezuela . Then they went to Central America. Now they are in North America. They travel about 390 miles a year. Each group of bees grows four times a year .This mea one million new grou every five years. Why are people afraid of killer bees ?People are afraid for two reaso .First ,the bees sting（叮）many more times than usual bees .Killer bees can sting sixty times a minute non-stop for two hours. Second ,killer bees attack in grou . Four hundred bee stings can kill a person. Already several hundred people are dead. Now killer bees are in Texas .In a few years they will reach all over the United States .People can do nothing but wait. 56．After the African bees lived together with the Brazilian bees ,they . A．made more honey B．made a new kind of bees C．made a mistake D．wanted to attack 57．Why are people afraid of killer bees? A．They increase fast . B．Several hundred people are dead. C．They sting more and attack in grou . D．They’re big and strong. 58．Where have killer bees reached now? A．North America. B．Brazil. C．Venezuela. D．All over the US 59．The best title of the pa age is . A．How to make more honey B．Killer bees C．A foolish scientist D．How to feed killer bees