Solution idea: Running water is better able to dissolve oxygen and nutrients than standing water. To make it rich in nutrients so the plants are healthier. Running water is healthier for plants than standing water.
Q: For plants, what is the difference between running and standing water?
Options:
- (A) wind and rain
- (B) precipitation
- (C) distance
- (D) healthier
- (E) seasons
- (F) temperature
- (G) heat produced
- (H) root growth
A: (D)

Solution idea: Insects may live in large colonies and have complex social behaviors. Insects are the only arthropod to have wings. Arthropods with wings may live in large colonies and have complex social behaviors.
Q: Arthropods with what may live in large colonies and have complex social behaviors.
Options:
- (A) fur
- (B) gills
- (C) animals
- (D) complex
- (E) Wasps
- (F) vertebrae
- (G) Flowers
- (H) wings
A: (H)

Solution idea: All life relies on a relatively narrow range of pH, or acidity. Acidity is measured with a pH meter or with pH paper strips. All life relies on a relatively narrow range of something you can measure with paper strips.
Q: What relies on a relatively narrow range of something you can measure with paper strips?
Options:
- (A) Length
- (B) voltage
- (C) all life
- (D) mammals
- (E) humans
- (F) Most plants
- (G) agriculture
- (H) animals
A: (C)

Solution idea: Plasma cells are activated B cells that secrete antibodies. Antibodies are manufactured by the immune system. Plasma cells are activated B cells that secrete immune system molecules.
Q: The molecules secreted by activated b cells are part of the:
Options:
- (A) immune system
- (B) Organic compounds
- (C) Energy.
- (D) an organism's body
- (E) acetic acid
- (F) harmful substances
- (G) Chemical energy
- (H) Veins and arteries.
A: (A)