Answer:
The germ theory of disease.
Explanation:
Ignaz Philipp Semmelweis is widely credited with the invention of the use of antiseptics in the reduction of puerperal fever in clinics.
However, the piece of scientific knowledge that he was missing to explain his discovery was the germ theory of disease.
The Roosevelt Corollary was an addition to the Monroe Doctrine. It stated that no European countries were allowed to intervene in Latin American affairs. The only way that the U.S was allowed to become involved was if the affairs or European countries was threatened.
Thank you anyway LOL points
A corduroy road<span> or </span>log road<span> is a type of </span>road made by placing logs<span>, perpendicular to the direction of the </span>road<span> over a low or swampy area. The result is an improvement over impassable mud or dirt </span>roads<span>, yet rough in the best of conditions and a hazard to horses due to shifting loose </span>logs<span>.</span>
