Antibiotics! According to the article, without doubt the invention of penicillin and other antibiotic drugs was the greatest discovery in the twentieth century. That is the true, but the lecturer claims that there are several problems with it today and the situation is not so good as it seems. First of all, since 1950 year antibiotic drugs have been used everywhere. The number of different kind of antibiotic have increased in many times compare with Fortieth years of twentieth century. However, according to the lecturer, the bacteria became more resistance than earlier. Over the years bacteria learns to survive and develop new conditions, new genes. So, we have to invent new drugs for each new bacteria. Secondly, according to the article, we overcame so dangerous diseases such as tuberculosis, by using streptomycin. On the other hand, the lecturer says that we have a problem with tuberculosis now. To illustrate this claim, lecturer says that twenty years ago people considered tuberculosis in the past, but now new cases of this disease appear oftener than earlier. It happens because bacteria change their genes and become resistance more and more. Now doctors use more than twenty millions of unit antibiotics, but people continue to die. Thus, doctores have to develop antibiotics step by step.