humans and how we can stop them in the future. As a result, Nathan 6 spends (spend) a lot of time in regions with wildlife. In the modern world humans ? square (not/stay) in one place anymore, and so new viruses also 8 square (travel) more easily. When humans 9 square (visit) different regions (for example Africa), they 10 square (not/realize) how easy it is to bring a new kind of disease back with them. However, the modern world with its technology also "I square (help) Nathan with his work. He often works in parts of the world where people 12 square (not/have) electricity. But a mobile phone allows Nathan to continue his life-saving work.