The United States is a federal union of 50states.The capital of national government is in Washington,D.C.The federal constitution setsup the structures of the national

government and listsits powers and activities.The constitution gives Congress the authority to makelaws which are necessary for the common defense and the good of the

nation.It also givesthe federal government the power to deal with national and internationalproblems that involve more than one state._________(46)

_________(47)Thelegislative branch makes the laws;the executive branch carries out the laws;andthe judicial branch interprets the laws.The President heads the executive

branch and theSupreme Court heads the judicial branch.The legislative branch includes bothhouses of Congress一 theSenate and the House of Representatives._________

(48)Forexample,Congress can pass a law; the President may sign it. Nevertheless,theSupreme Court can declare the law unconstitutional and nullify（取消）it.

__________(49)ThePresident and the members of the Congress are elected directly.But the heads offederal departments and Supreme Court judges are appointed by the

President. Everycitizen votes in secret.__________(50)The people believe that their governmentshould provide a framework of law and order within which they are left free

to run their ownlives.

_________（49）

A.The election of governmenttakes place every four years.

B.The federalgovernment has three branches:the executive,the legislative,and the judicial.

C. All the powersthat are not given to the federal government by the constitution are theresponsibility of the individual states.

D.The United Statesgovernment is based on the principle of federalism,in which power is sharedbetween the federal government and state governments.

E.Consequently,noone knows for sure whether his neighbor actually votes for or against aparticular candidate.