Birds that do not receive adequate nutrition during development sing less often and for shorter periods of time as adult birds. Which best describes the outcome of nutritional stress in these songbirds?
A: They are less likely to attract mates and pass on their genes.

Both hurricanes and tornadoes always ___.
A: have high winds

Animals use resources in the environment to survive. Which of the following resources does an animal use for energy?
A: food

Examine each of these chemical equations to determine which equation is correctly balanced.
A:
Mg(NO_{3})_{2} + K_{2}CO_{3} -> MgCO_{3} + 2KNO_{3}