Problem: OPTIONS:
- endocell
- xygote
- exosperm
- endosperm
Q: Q: What does the central cell develop into after double fertilization? A:
Answer: endosperm

Problem:OPTIONS:
- fixation fractions
- mesh fractions
- atom fractions
- mole fractions

Q: What is used to describe gas concentrations of a solution? A:
****
A: mole fractions

Q: The innermost layer of the sun is known as what? A:
OPTIONS:
- photosphere
- surface
- convective zone
- core
core

Q: Do waves move faster when particles are close to each other or far away? A:
OPTIONS:
- unaffected
- far away
- open
- close

Answer: close

Question: Q: What organ system is comprised of your heart, blood, and blood vessels all working together? A:
OPTIONS:
- thoraxic system
- nervous system
- digestive system
- cardiovascular system
Answer: cardiovascular system

input: OPTIONS:
- a toxic reaction
- a bio reaction
- a thermodynamic reaction
- a chemical reaction Now, answer this question: Q: What is a process in which some substances change into different substances? A:
A:
output:
a chemical reaction