Problem: OPTIONS:
- tropic and subtropic
- pheromones and enzymes
- endorphins and adrenaline
- tropic and sex
Q: Q: What two types of hormones regulate mammalian reproduction? A:
Answer: tropic and sex

Problem:OPTIONS:
- iodine and magnesium
- sodium and magnesium
- xerophyte and magnesium
- iron and magnesium

Q: What elements do mafic minerals typically include? A:
****
A: iron and magnesium

Q: What celestial body in the solar system makes up most of its total mass? A:
OPTIONS:
- Jupiter
- earth
- Andromeda
- sun
sun

Q: In the freshwater flatworms, protonephridia serve chiefly in what? A:
OPTIONS:
- enculturation
- excretion
- thermoregulation
- osmoregulation

Answer: osmoregulation

Question: Q: Unlike wild animals, what type of species are genetically uniform, making them more vulnerable to die-out from disease? A:
OPTIONS:
- free-range species
- urbane species
- mammals
- domestic species
Answer: domestic species

input: OPTIONS:
- one
- five
- three
- four Now, answer this question: Q: How many major forces of elevation cause allele frequencies to change? A:
A:
output:
four