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For question three, only answer part B, using the Codification of Presidential Proclamations and Executive Orders. This will be easiest to do if you use the numeric index available in that source.
To complete question 4, Google the phrase "no employee of the United States government shall engage in, or conspire to engage in, political assassination" From your search results, select one that provides the complete text of the executive order and you would feel confident citing.
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You can answer these questions by going directly to the websites or by using the US Government Manual. If any of the website links has changed, use USA.gov to find the current link.