what are two methods that can be used to ensure that the experiemental and control groups are equivalent

Which was an effect of the nuclear disaster at chernobyl, ukraine? people and animals did not get sick. drinking water was unsafe for a long time. forests got healthier than they had been. all the nuclear power plants in the world were closed.

Explain how the ideas of karl marx came to influence american workers in the late 1800s

50 points in at least two paragraphs, discuss the differences between the principles of republicanism and democracy. explain whether you think the united states is more of a republic or a democracy. refer to at least one example from the constitution.