With the development of science, human life has changed tremendously. People living in the 18th or 19th centuries would never imagine the advanced household appliances we are now able to enjoy. Every aspect of our lives, for instance, in the field of medicine or agriculture, has witnessed great improvements through the application of science.
However, many people complain that science has also brought disasters to human life. Some evil scientists have used their knowledge to do some illegal things. They may use science for the creation of weapons to destroy thousands of lives in wars; they might also use their knowledge to produce drugs to make a lot of money for themselves.
Generally speaking, science has provided us with many valuable things. But if used wrongly, it can also lead to harm. We should try to keep science under our control and put it to the best use for mankind.