Here are the answers to your questions:
Question 1: The revolution in D. Russia is one of the many events that helped to make for uncertain times at the start of the First Red Scare.
Question 2: The post-World War I law that made it a felony to make "disloyal remarks" against the U.S. is the C. Sedition Act.
Question 3: A. Palmer Raids were a crackdown on groups or people that might be considered dangerous to U.S. security.