Q: Fact: most canyons are formed by flowing rivers through erosion over long periods of time
Question: Which two forces are likely the cause of canyons?

A: water plus gravity

Q: Fact: wind is an inexhaustible resource
Question: The main reason people want to use wind as an energy source is because there is

A: an everlasting supply

Q: Fact: the sun is located directly overhead at noon
Question: The sun was straight above us when we

A: took a break

Q: Fact: a bird is warm-blooded
Question: Which of the following is a true statement?

A:
a robin has warm blood