List the decades that encompassed the 2nd industrial revolution

The Second Industrial Revolution was a phase of rapid industrialization from the late 19th century into the early 20th century.

Explanation:

While the 1st Industrial Revolution caused the development of businesses, for example, coal, iron, railways, and materials, the Revolution saw the extension of power, oil, and steel.

The 2nd Industrial Revolution was significantly affected in America. As industries developed and extended, large organizations framed. Numerous enterprises created during this timeframe. For laborers, this regularly implied poor wages, extended periods, and unfortunate working conditions.

answer; (a) he was a u.s senator for 38 years;

a. theta waves. this is because the person is in a light sleep which means the brain waves would show these kind of waves.