Why did earlier historians consider the medieval period the "dark ages"?

They were called the Dark Ages because there were so many knights! xD Jk

Between the fall of the Roman Empire and the Renaissance there was a period of cultural and intellectual stagnation in Europe. There was no progress made, no development. in fact things went backwards. This period was known as the Dark age. People consider this the dark age because not a lot of major things happened. A few things here and there but nothing significant. 'The power of the church' would probably the key phrase I would recommend you use, though, because the church was the most powerful influence in the intellectual stagnation of that period. Hope I helped.  :)

battle of saint-mihiel, (12–16 september 1918), allied victory and the first u.s.-led offensive in world war i. the allied attack against the saint-mihiel salient provided the americans with an opportunity to use their forces on the western front en masse.

explanation:

hello there!

the graphics that you have attached within the question, indicates that few people in bolivia work in industry according to its labor force.

however, the graphic that is on the right side of the picture shows the gdp sector in bolivia. this gross domestic product is a macroeconomic magnitude   that shows the monetary value of all finished goods and services within a country's borders in a specific time period. in this case, the graphic is showing the monetary value in each sector -agriculture, industry and services- of bolivia in 2012.

so, although the first graphic located at the left side indicates that not so many people work in industry, this is the second most important sector according to the gdp metrics because of the monetary value that impacts on its country. it does not need to be the most valuable one. if it makes an impact on the country's economy, it will be definitely crucial to it.