Why did the pope call for the crusade

Is christianity monothestic or polythesitic?

As our current atmosphere formed, the concentrations of various atmospheric gases fluctuated. match each gas with the explanation that best describes how its proportion changed during the evolution of the atmosphere.

This chart shows the number of soldiers killed according to two different sources. source a is a book written by university professors. source b is from a well-known historical website. in a paragraph, explain why the data presented is different, and evaluate the reliability of each source. which should be used in a school research project, and why?