As cheif executive, a president must do which of the

As a chief executive, the President is the leader for the millions of workers in the government in the Executive branch or office. He or she will be the one to decide how the United States' laws are to be implemented or enforced. He or she will also choose advisors and officials to help him run the Executive office or branch. 

Assemblies do not have written codes of laws. laws are matters for magistrates and courts, not assemblies. codes of law are things such as civil law, criminal law, and constitutional law. what assemblies have are procedures regarding debating, voting and other business they might carry out.  also note that rome had three assemblies: the assembly of the soldiers, the assembly of the tribes, and the plebeian councils.