Problem:OPTIONS:
- reptiles
- amphibians
- insects
- mammals

Q: A major diversification of what animal group occurred about 50 million years ago, possibly spurred by worldwide climate change? A:
****
A: mammals

Q: What increases the size of a population's gene pool? A:
OPTIONS:
- mass extinction
- microbes
- natural selection
- mutations
mutations

Q: Many organisms look very similar to other organisms because they may be from the same what? A:
OPTIONS:
- nutrients
- area
- parasites
- species

Answer: species

Question: Q: Fluoride ion is widely used in water supplies to help prevent what? A:
OPTIONS:
- rust
- bacteria
- chlorine taste
- tooth decay
Answer: tooth decay

input with options: Q: What is something that all machines must overcome? A:
OPTIONS:
- stress
- work
- temperature
- friction
output: friction

Problem: OPTIONS:
- sound transmission
- GPS
- radar
- sonar
Q: Q: Sound navigation and ranging is an acronym for what, which is used to locate underwater objects such as submarines? A:
Answer:
sonar