During the second industrial revolution, which building material became one of the most important in the world?

john locke studied medicine and he laid a lot of groundwork for the enlightenment he also contibutied to the development of liberalism

richard milhous nixon (january 9, 1913 – april 22, 1994) was the 37th president of the united states, serving from 1969 to 1974, when he became the only president to resign (quit). he is also known for corruption and the watergate scandal which resulted in the public losing trust in him and his resignation.