Problem:OPTIONS:
- time
- plate tectonics
- earthquakes
- plate movements

Q: What causes continents to drift closer to the poles or the equator? A:
****
A: plate movements

Problem:OPTIONS:
- antecedent - oncogenes
- anti-oncogenes
- extinction - oncogenes
- proto-oncogenes

Q: What are mutant versions of normal genes called? A:
****
A: proto-oncogenes

Problem:OPTIONS:
- five
- two
- one
- three

Q: How many dimensions can humans see in? A:
****
A: three

Problem:OPTIONS:
- common rain
- toxic rain
- heavy rain
- acid rain

Q: Nitrogen and sulfur oxides form what type of rain? A:
****
A:
acid rain