The killer bees are coming! By the time you read this they will have reached Texas. By the

mid-1990s, they will have reached all the warmer areas of the United States. Scientists as well as farmers wait for them with a mixture of fear and wonder.

The killer bees should not be coming at all. Nature did not put them on this direct path for the United States; human beings did. The killer bees are from Africa. But in 1957 a scientist from Brazil got some of these killer bees for his experiments. The aim was to produce a better bee. However, an accident happened: a guest beekeeper let twenty-six of the queen bees escape by mistake. Before long, groups of killer bees took off for the woods.

Since that time, the wild killer bees have multiplied(繁衍) many times over. By 1998, their population was over 1015. They have spread all over South America, Central America, and most of Mexico. The United States is the next stop.

Are the killer bees really killers？ Yes, they are. In their first thirty years in America, they have killed thousands of hens, pigs, and other animals. While no one knows the exact number, it is believed that several hundred people have also been killed.

So be careful. Killer bees are on the way. Scientists have no idea what to do with them yet. There must be a way.

We know from the passage that killer bees will spread to the United States ______.

A．from north

B．from south

C．from west

D．from east