Fill in the blank with a suitable word

It seems entirely natural to us that there are teams of scientists in universities and (46) _______ institutions around the world, attempting to discover the way the world works. (47) _______, it hasn’t always been that way. Although the scientific method is now four or five hundred years old, the ancient Greeks, for example, believed that they could (48) _________ the cause of natural events just by the power of thought. During the 17th century, more and more people began to realize that they could test their scientific ideas by designing a relevant experiment and seeing what happened. A lot of (49) _________ was made in this way by individual scientists. These men and women often worked alone, carrying out research into many different areas of science, and they often received very little (50) _________ for their hard work. At the start of the 20th century, though, it became clear that science was becoming more complicated and more expensive. The individual scientists disappeared, to be replaced by highly qualified teams of experts. Modern science was born.