Problem: OPTIONS:
- high density
- large mass
- gravity
- gas bubble holes
Q: Q: What helps pumice float in water? A:
Answer: gas bubble holes

Problem:OPTIONS:
- toxins
- particles
- particulates
- ions

Q: What do atoms become if they lose or gain electrons? A:
****
A: ions

Q: In which supergroup are red algae and green algae included? A:
OPTIONS:
- xerophyte
- spirogyra
- troglodyte
- archaeplastida
archaeplastida

Q: The fossil record shows that this type of event is followed by the evolution of new species to fill the habitats where old species lived? A:
OPTIONS:
- minor extinction
- moderate extinction
- formation extinction
- mass extinction

Answer: mass extinction

Question: Q: Mountain building and earthquakes are some of the responses of rocks when subected to what? A:
OPTIONS:
- time
- erosion
- weather
- stress
Answer: stress

input: OPTIONS:
- food
- air
- habitat
- water Now, answer this question: Q: Desert plants have special stems and leaves to conserve what? A:
A:
output:
water