The constitutional power to appoint ambassadors and to negotiate treaties is vested in the

Constitutionally, the power to appoint ambassadors and to negotiate treaties is vested in the President. The President also has the power to appoint other public Ministers and Consuls, Judges of the Supreme Court, and all other Officers of the United States. The constitution however adds that these powers shall be exercised by and with the Advice and Consent of the Senate. 

question 10: the answer is c, to their constituents address a problem.

question 11: i think it would be domestic bills, which deal with american issues only and public bills, which affect the whole nation.