One of the most important non-legislative functionsof the U.S Congress is the power to investigate.

　　The power is usually delegated to committees—eitherstanding committees, special

　　committees set for a specific purpose, or jointcommittees __1__

　　consisted of members of both houses. Investigations__2__

　　are held to gather information on the need for future

　　legislation,to test the effectiveness of laws already passed, to inquire into thequalifications and performance of

　　members and officials of the other branches, and in rare occasions, __3__

　　to lay the groundwork for impeachment proceedings. Frequently,

　　committees rely outside experts to assist in conducting __4__

　　investigative hearings and to make out detailed studies of issues. __5__

　　There are important corollaries to the investigative power.

　　One is the power to publicize investigations and its results. Most __6__

　　committee hearings are open to public and are reported widely __7__

　　in the mass media. Congressional investigations nevertheless __8__

　　represent one important tool available to lawmakers to inform

　　the citizenry and to arouse public interests in national issues, __9__

　　Congressional committees also have the power to compel

　　testimony from unwilling witnesses, and to cite for contempt

　　of Congress witnesses who refuse to testify and for perjury

　　these who give false testimony. __10__