12. Johannes Gutenberg's printing press made it possible to manufacture large numbers of books for relatively little cost for the first time. Books and other printed matter consequently became available to a wide general audience, greatly contributing to the spread of literacy and education in Europe.
13. Four common causes, as recognized by social scientists, are technology, social institutions, population, and the environment. All four of these areas can impact when and how society changes. And they are all interrelated: a change in one area can lead to changes throughout.
The conclusion is that although a US president can technically send troops into a foreign country, in order to lawfully declare war, he or she must get the approval of Congress.
The unwritten constitution includes the practice of judicial review. Judicial review is the idea that the actions of the legislative and executive branches of the United States government are subject to review by the Judicial branch!
