1. An interest group is:
an organization of people who share a common interest and work together to protect and promote that interest by influencing the government
An interest group can be liberal or conservative or centrist. Interest groups exist on many levels across the spectrum of political concerns.
2. Television, radio, newspapers, and the Internet are all examples of :
media
Means of mass communication are referred to as "media" and exist in various forms. All the listed examples are used in the 21st century, but all go back to roots before the 21st century. Even the Internet began public commercial use already in the last decade of the 20th century.
3. Place the terms in their correct order from left to right on the traditional political spectrum:
radical, liberal, moderate, conservative, reactionary
Probably you got that liberal is to the left of moderate, and conservative tends toward the right. In politics, a "radical" is on the far left, someone who wants complete political or social reform. A "reactionary" is one who thoroughly opposes all social liberalization and major reforms.