A deadly infection outbreak swept through a small city in Zaire, Africa last spring, killing more than one hundred people. It was a terrible situation.(1) ___________________________________________________. As scientists rushed to control the outbreak, people in the U.S. wonder whether it could attack here. "We are foolish if we think it couldn't come to our country. We can never be too careful when we face some disease, especially the infectious one." say doctors. The virus can be highly infectious. (2) __________________________________________________. That's what scientists believe happened in Zaire. The healthcare workers who treated the first victim there soon fell ill, too. The problem was that they had no protective equipment to prevent themselves from being infected.International rescue works brought equipment to Zaire soon after the outbreak occurred. Now the disease appears to be under control, but no one can promise that for 100 percent .One big mystery is that no one knows where the virus comes from or where it will strike next. (3) ____________________________________________. Then it somehow finds its way to infect humans. Scientists are now headed to the jungles of Africa to find out where the virus lives .Once they find the virus, they also hope to find ways to combat it.