Which of the following is not a power of congress? to establish post offices to maintain postal roads to maintain a state road to issue a patent

Congress does not have the power to maintain postal roads.

Hope this helps.

no every country is held to the same degree as others just some member countries such as the usa and germany are more economically sound so the need to show there support to all others  

interest groups send representatives to state capitals and to washington, d.c. to put pressure on members of congress and other policymakers. they engage in lobbying, or the organized process of influencing legislation or policy. lobbying can take many forms. interest groups can testify in congressional hearings.