Q: In clear weather, a bright light can be seen for a long distance. In conditions of heavy fog, the visibility is greatly reduced. Which of the following explains the reduced visibility? OPTIONS:
- Light is refracted by water vapor in the air.
- Light is scattered by water droplets in the air.
- Light is absorbed by water vapor near the ground.
- Light is reflected by water droplets on the ground.
A: Light is scattered by water droplets in the air.

Q: Which factors can have the greatest effect on the health of a river system? OPTIONS:
- type of soil and salinity
- nitrate levels and turbidity
- human consumption and pH
- natural disasters and tidal changes
A: nitrate levels and turbidity

Q: Rocks are classified as igneous, metamorphic, or sedimentary according to OPTIONS:
- their color
- their shape
- how they formed
- the minerals they contain
A: how they formed

Q: In animal skin tissue, cell division is responsible for OPTIONS:
- growth and repair
- sexual reproduction
- obtaining energy
- production of sex cells
A:
growth and repair