A, invented by stephen h. horgan, changes continuous tones into dots of varying sizes. squares are formed by horizontal and vertical rules etched on pieces of glass. the amount of light that passes through each square determines how big each dot should be.

The answer is the Half Tone method. Stephen H. Horgan invented this methond in 1873 while working at the New York Herald. He was fired shortly after because the New York Herald editor thought that the Half Tone Method was an ineffective procedure.

In the picture attached to this answer, it can be seen how greatly the quality of the imagen is improved using the method. The nature of it is exactly as described in the question.

the answer is a glaciers carved a large valley that later flooded and became puget sound

the answer is d. tariffs were raised by america's trading partners after the smoot-hawley tariff act, decreasing exports, and declining job rates.