Which of these will best separate a saltwater solution? OPTIONS:
- using a paper filtering system
- using chromatography
- allowing the salt to settle
- allowing the water to evaporate
A: allowing the water to evaporate

Which biological activity occurs in a repeated rhythm? OPTIONS:
- sneezing
- coughing
- breathing
- blinking
A: breathing

What do all mammals have in common that distinguishes them from birds? OPTIONS:
- eyes
- fur
- a brain
- a heart
A: fur

A shallow container of salt water is placed in sunlight for a day. Which is the most likely result? OPTIONS:
- All of the mixture will evaporate.
- The salt will keep the water from evaporating.
- The salt will separate from the water and float at the top of the container.
- Only the water will evaporate and the salt will remain in the container.
A:
Only the water will evaporate and the salt will remain in the container.