Lemon juice turns litmus paper red, is corrosive and tastes sour. Lemon juice is classified as OPTIONS:
- an acid.
- a base.
- an element.
- More information is needed to classify lemon juice.
A: an acid.

When the Northern Hemisphere is tilted toward the Sun, what season is occurring in Australia? OPTIONS:
- fall
- winter
- spring
- summer
A: winter

When cold weather freezes water in the cracks of rocks, which would most likely happen? OPTIONS:
- The rocks would become rounded.
- The rocks would be used for shelter.
- The rocks would be moved by the wind.
- The rocks would break into smaller pieces.
A: The rocks would break into smaller pieces.

A scientist was investigating why several fish caught from a local stream displayed similar mutations. He found that the water temperature of the stream was elevated since an industrial plant began discharging heated water into the stream. The scientist concluded that increased water temperature during the egg phase led to the mutation in the fish. According to this conclusion, the mutation was caused by OPTIONS:
- an autoimmune disorder.
- a congenital defect.
- an environmental condition.
- an injury from a predator.
A:
an environmental condition.