Problem: OPTIONS:
- nervous system
- lung
- heart
- brain
Q: Q: The skull is a part of a vertebrate endoskeleton that encloses and protects what organ? A:
Answer: brain

Problem:OPTIONS:
- lungs
- layers
- pores
- gills

Q: What do fish have that allow them to "breathe" oxygen in water? A:
****
A: gills

Q: What makes a complete orbit around the earth once every 29 1/2 days? A:
OPTIONS:
- Mars
- the Sun
- Gemini
- the moon
the moon

Q: Root systems are mainly of two types. dicots have a tap root system, while monocots have a what? A:
OPTIONS:
- long root system
- runner root system
- attaching root system
- fibrous root system

Answer: fibrous root system

Question: Q: Why do comet tails always point away from the sun instead of trailing behind the comet? A:
OPTIONS:
- dust particles attract
- dust particles evaporate
- dust particles liquify
- dust particles recoil
Answer: dust particles recoil

input: OPTIONS:
- velocity
- temperature
- color
- mass Now, answer this question: Q: A spontaneous change process called neutrino oscillations can occur only if neutrinos have what property? A:
A:
output:
mass