18. The main duty of the Congress is to make laws, including those which levy taxes that pay for the work of the federal government.A law begins as a proposal called a“bill"(提案).It is read, studied in committes,commented on and amended in the Senate or house chamber in which it was introduced.It is then voted upon.If it passes,it is sent to the other house where 18. The main duty of the Congress is to make laws, including those which levy taxes that pay for the work of the federal government. A law begins as a proposal called a “bill”(提案). It is read, studied in committes, commented on and amended in the Senate or house chamber in which it was introduced. It is then voted upon. If it passes, it is sent to the other house where