Answer:
C. Chemical weapons.
Explanation:
TL:DR Chemical gas is a war crime due to the amount of suffering it causes. Mustard gas burns the skin, Phosgene is impossible to see, and Chlorine can make you drown in your own body.
Machine guns had been in use and invented since 1908, with invention of weapons such as the Vickers and German Maschinegewehr 08. Trench warfare wasn't a weapon, but more of a tactic. Mines weren't a war crime either as they most likely weren't deemed to cause "unneeded suffering" and their purpose usually was to simply discourage the travel of an area. Usually, if you stepped on a mine you'd die.
Meanwhile, Chemical gas was simply invented on accident as the German Empire's scientist,
A. Banned Chinese immigration to the United States for 10 years
Explanation:
The Chinese Exclusion Act of 1882 suspended Chinese immigration for ten years and declared Chinese immigrants ineligible for naturalization. President Chester A. Arthur signed it into law on May 6, 1882.
Cyanobacteria, also known as "blue-green algae", are the unicellular organisms which are able to produce oxygen.
Approximately 540 years ago, the atmosphere was very poor on oxygen. Cyanobacteria are thought to be responsible for the oxidization of the atmosphere back then, in an event known as <em>"The Great Oxygenation Event"</em>. As a result, Earth's life forms suffered drastic changes in their composition, as they evolved from being <em>anaerobic</em> to becoming organisms <em>highly dependant</em> on oxygen. The oxygenation of the atmosphere would eventually provide the adequate environment in order for the <em>Cambrian Explosion</em>, or the first diversification of living organisms, to happen.
Most economies are considered mixed because most have some portion of the means of production under government control. Most economic systems also have some element of the market or capitalism. ... The most vulnerable members of society benefit from a mixed economy because they are offered some social safety net.
Jesus Christ was the person Christians believed was the jewish messiah.