I shift around, though always slowly. I never move more than a few inches at a time. A large movement by me can kill many people. I am huge, yet unseen by humans. What am I?
Answer: A tectonic plate.
This riddle appears in the following downloadable PDF files:
Can you solve one of the most famous logic puzzle ever?
Memory Matching game for kids, adults and seniors.
Connect the matching tiles and pop them all.