Q: Q: When salinity and pressure increase, or when temperature decreases, what happens to water density? A:

OPTIONS:
- fluctuates
- drops
- stays the same
- increases

A: increases

input: OPTIONS:
- food
- space
- products
- energy Now, answer this question: Q: What do chemical reactions need to be activated? A:
A:
output: energy

Q: Which cycle tracks the flow of nitrogen through an ecosystem? A:

OPTIONS:
- nitrogen reaction
- water cycle
- life cycle
- nitrogen cycle

Answer: nitrogen cycle

Problem: OPTIONS:
- zirconium
- zenon
- hydrogen
- carbon
Q: Q: The hardest natural substance, diamond is a form of what element? A:
Answer: carbon

Problem:OPTIONS:
- dermis
- tendons
- muscles
- meninges

Q: The three layers of protective coverings of the spinal cord is called what? A:
****
A: meninges

Problem:OPTIONS:
- moving things
- changing molecules
- removing barriers
- changing a force

Q: A machine is any device that makes work easier by doing what? A:
****
A:
changing a force