Because the most important things are not forgotten
They have been found on oracle bones
Answer:
While experimenting researcher can record, test or control the group and while observational study researcher can't do that
Explanation:
An experimental study can be under the control of someone who is doing the research or experiment.
The researcher can also manipulate the experiment and in the observational study, there are no experiments.
The observational study requires the research observing of something, this observing includes what happened in the past, what is saw in the past and what is now.
The military actions taken by the United States against international communism when American Soldiers fought against the Red Army during the Russian civil war.
On June 20, 1948, the US and their allies had their first major cold war aiming to stop the mass murderer and tyrant Joseph Stalin from enslaving people in Europe. The massive effort took the Soviets by surprise. The move in Berlin also proved a grave political mistake by Stalin. To prevent the expansion of communism, The Truman Doctrine also called the Policy of containment was President Harry Truman's foreign policy.
The Truman Doctrine stated that The US would provide political, military, and economic aid to democratic countries under threat of communist influences.
Learn more about Communism here brainly.com/question/12173354
#SPJ4
