Science quiz hot shot!

How much science should a high school graduate know?

If you had to pick a single question (science question) that you think anybody who went through 12 years of school should be able to answer, what would your question be?

The Star Tribune recently polled teachers, institute heads and some Nobel Prize winners to come up with this list (you can find it here) -

1. What percentage of the earth is covered by water?

2. What sorts of signals does the brain use to communicate sensations, thoughts and actions?

3. Did dinosaurs and humans ever exist at the same time?

4. What is Darwin's theory of the origin of species?

5. Why does a year consist of 365 days, and a day of 24 hours?

6. Why is the sky blue?

7. What causes a rainbow?

8. What is it that makes diseases caused by viruses and bacteria hard to treat?

9. How old are the oldest fossils on earth?

10. Why do we put salt on sidewalks when it snows?

Extra credit: What makes the seasons change?