【答案解析】{{B}} Duality of Science: Its Positive Effects and Side Effects{{/B}} So far, human society has undergone three revolutions, i.e. Agricultural Revolution, Industrial Revolution and Information Revolution. Every revolution is the result of science. In this sense, science is the instrument of social progress. It almost always brings to humankind a blessing. It is science that brings human beings from primitive caves gradually to cozy and comfortable dwelling houses, from shabby cotton clothes to various good-quality wearing apparel, from simple food to various kinds of nutritious food. However, science has its side effects. For instance, the automobile facilitates people% movement from one place to another, but it has left overcrowded highways and air pollution. Fertilizers have increased crop production but also increased the growth of algae in lakes and canals. Nuclear power plants have increased available energy but led to storage problems, life-threatening contamination, and at least one accident with worldwide repercussions. Based on the above discussion, we can conclude that science is a mixed blessing. The most important thing for us to do is to make the best use of the positive effects of science and try our best to reduce the loss a scientific product or activity may bring us. In addition, we must prevent scientific products or activities from being misused by evil people.