Answer: I. Veto power
II. Executive order
Explanation: To ensure a separation of powers, the U.S. Federal Government is made up of three branches: legislative, executive and judicial. The Executive Branch, headed by the President, proposes laws; the Legislative Branch, Congress, writes and passes the laws and the Judicial Branch interprets the law and the Constitution.
Under the US constitution, the executive branch gives veto power to the president, allowing the president to keep the legislative branch in check. Also, the executive branch can also declare executive orders, effectively proclaiming how certain laws should be enforced.