Problem: Who was the famous comic book creation of Frank Hampson?
Answer: dan dare

Problem: An American mathematician, who engaged in a mail bombing campaign that spanned nearly 20 years, killing three people and injuring 23 others, by what name is Ted Kaczynski popularly known?
Answer: unabomber

Problem: What does the prefix 'cry' mean in words such as cryogenics?
Answer: cold

Problem: What is the formation of vapour bubbles of a flowing liquid in a region where its pressure falls below its vapour pressure?
Answer:
cavitation